diff --git a/src/TensorAlloc.zig b/src/TensorAlloc.zig
index d1c47b8..68b400d 100644
--- a/src/TensorAlloc.zig
+++ b/src/TensorAlloc.zig
@@ -3,6 +3,7 @@ const Scales = @import("Scales.zig");
 const UnitScale = Scales.UnitScale;
 const Dimensions = @import("Dimensions.zig");
 const Dimension = Dimensions.Dimension;
+const Allocator = std.mem.Allocator;
 const sh = @import("shared.zig");
 
 // ─────────────────────────────────────────────────────────────────────────────
@@ -50,11 +51,11 @@ pub fn TensorAlloc(
 
         // Specific to Alloc
 
-        pub fn init(allocator: std.mem.Allocator) !@This() {
+        pub fn init(allocator: Allocator) !@This() {
             return .{ .data = try allocator.create(Vec) };
         }
 
-        pub fn deinit(self: @This(), allocator: std.mem.Allocator) void {
+        pub fn deinit(self: @This(), allocator: Allocator) void {
             allocator.destroy(self.data);
         }
 
@@ -72,7 +73,7 @@ pub fn TensorAlloc(
         }
 
         /// Broadcast a single value across all elements.
-        pub inline fn splat(alloc: std.mem.Allocator, v: T) !Self {
+        pub inline fn splat(alloc: Allocator, v: T) !Self {
             const new = try @This().init(alloc);
             new.data.* = @splat(v);
             return new;
@@ -88,7 +89,7 @@ pub fn TensorAlloc(
 
         /// Element-wise add.  Dimensions must match; scales resolve to finer.
         /// RHS must have the same shape as self, or total == 1 (broadcast).
-        pub inline fn add(self: *const Self, rhs: anytype) TensorAlloc(
+        pub inline fn add(self: *const Self, alloc: Allocator, rhs: anytype) !TensorAlloc(
             T,
             dims.argsOpt(),
             sh.finerScales(Self, @TypeOf(rhs)).argsOpt(),
@@ -102,10 +103,16 @@ pub fn TensorAlloc(
             if (comptime RhsType.total != 1 and !sh.shapeEql(shape, RhsType.shape))
                 @compileError("Shape mismatch in add: element-wise operations require identical shapes, or a scalar RHS.");
 
+            var area = std.heap.ArenaAllocator.init(alloc);
+            defer area.deinit();
+
             const TargetType = TensorAlloc(T, dims.argsOpt(), sh.finerScales(Self, RhsType).argsOpt(), shape);
-            const l: Vec = self.to(TargetType).data;
-            const r: Vec = rhs.to(TargetType).data;
-            return .{ .data = if (comptime sh.isInt(T)) l +| r else l + r };
+            const l: TargetType = try self.to(area.allocator(), TargetType);
+            const r: TargetType = try rhs.to(area.allocator(), TargetType);
+
+            const new = try TargetType.init(alloc);
+            new.data.* = if (comptime sh.isInt(T)) l.data.* +| r.data.* else l.data.* + r.data.*;
+            return new;
         }
 
         /// Element-wise sub.  Dimensions must match; scales resolve to finer.
@@ -226,8 +233,9 @@ pub fn TensorAlloc(
         ///   • Scale ratio is computed fully at comptime; only a SIMD multiply at runtime.
         pub inline fn to(
             self: *const Self,
+            alloc: Allocator,
             comptime Dest: type,
-        ) Dest {
+        ) !Dest {
             if (comptime Self == Dest) return self.*;
 
             // Run validation checks FIRST before dealing with types
@@ -236,74 +244,85 @@ pub fn TensorAlloc(
             if (comptime total != 1 and !sh.shapeEql(shape, Dest.shape))
                 @compileError("Shape mismatch in to: destination type must have the identical shape, or be a scalar.");
 
-            const vec = if (comptime total == 1 and Dest.total != 1)
-                TensorAlloc(Dest.ValueType, dims.argsOpt(), scales.argsOpt(), Dest.shape){ .data = @splat(self.data[0]) }
-            else
-                self;
-
             const ratio = comptime (scales.getFactor(dims) / Dest.scales.getFactor(Dest.dims));
             const DestT = Dest.ValueType;
             const DestVec = @Vector(Dest.total, DestT);
+            const T_info = @typeInfo(T);
+            const Dest_info = @typeInfo(DestT);
 
-            if (comptime ratio == 1.0 and T == DestT)
-                return .{ .data = vec.data };
+            const vec = try TensorAlloc(Dest.ValueType, dims.argsOpt(), scales.argsOpt(), Dest.shape).splat(
+                alloc,
+                if (comptime T_info == .int and Dest_info == .int)
+                    @as(DestT, @intCast(self.data[0]))
+                else if (comptime T_info == .float and Dest_info == .float)
+                    @as(DestT, @floatCast(self.data[0]))
+                else if (comptime T_info == .int and Dest_info == .float)
+                    @as(DestT, @floatFromInt(self.data[0]))
+                else if (comptime T_info == .float and Dest_info == .int)
+                    @as(DestT, @intFromFloat(self.data[0]))
+                else
+                    unreachable,
+            );
+            if (comptime total != 1 and total == Dest.total)
+                vec.data.* = if (comptime T_info == .int and Dest_info == .int)
+                    @as(DestVec, @intCast(self.data.*))
+                else if (comptime T_info == .float and Dest_info == .float)
+                    @as(DestVec, @floatCast(self.data.*))
+                else if (comptime T_info == .int and Dest_info == .float)
+                    @as(DestVec, @floatFromInt(self.data.*))
+                else if (comptime T_info == .float and Dest_info == .int)
+                    @as(DestVec, @intFromFloat(self.data.*))
+                else
+                    unreachable;
+            defer vec.deinit(alloc);
 
-            // If ratio is 1, handle type conversion correctly based on BOTH source and dest types
-            if (comptime ratio == 1.0) {
-                const T_info = @typeInfo(T);
-                const Dest_info = @typeInfo(DestT);
+            const new = try Dest.init(alloc);
 
-                return .{
-                    .data = if (comptime T_info == .int and Dest_info == .int)
-                        @as(DestVec, @intCast(vec.data))
-                    else if (comptime T_info == .float and Dest_info == .float)
-                        @as(DestVec, @floatCast(vec.data))
-                    else if (comptime T_info == .int and Dest_info == .float)
-                        @as(DestVec, @floatFromInt(vec.data))
-                    else if (comptime T_info == .float and Dest_info == .int)
-                        @as(DestVec, @intFromFloat(vec.data))
-                    else
-                        unreachable,
-                };
-            }
+            if (comptime ratio == 1.0)
+                return new;
 
             if (comptime T == DestT) {
-                if (comptime @typeInfo(T) == .float)
-                    return .{ .data = vec.data * @as(DestVec, @splat(@as(T, @floatCast(ratio)))) };
+                if (comptime @typeInfo(T) == .float) {
+                    new.data.* = vec.data.* * @as(DestVec, @splat(@as(T, @floatCast(ratio))));
+                    return new;
+                }
 
                 if (comptime ratio >= 1.0) {
                     const mult: T = comptime @intFromFloat(@round(ratio));
-                    return .{ .data = vec.data *| @as(Vec, @splat(mult)) };
+                    new.data.* = vec.data.* *| @as(Vec, @splat(mult));
                 } else {
                     const div_val: T = comptime @intFromFloat(@round(1.0 / ratio));
                     const half: T = comptime @divTrunc(div_val, 2);
 
                     if (comptime @typeInfo(T).int.signedness == .unsigned) {
-                        return .{ .data = @divTrunc(vec.data + @as(Vec, @splat(half)), @as(Vec, @splat(div_val))) };
+                        new.data.* = @divTrunc(vec.data.* + @as(Vec, @splat(half)), @as(Vec, @splat(div_val)));
                     } else {
-                        // Vectorized branchless negative handling
-                        const is_pos = self.data >= @as(Vec, @splat(0));
+                        const is_pos = self.data.* >= @as(Vec, @splat(0));
                         const offsets = @select(T, is_pos, @as(Vec, @splat(half)), @as(Vec, @splat(-half)));
-                        return .{ .data = @divTrunc(vec.data + offsets, @as(Vec, @splat(div_val))) };
+                        new.data.* = @divTrunc(vec.data.* + offsets, @as(Vec, @splat(div_val)));
                     }
                 }
+
+                return new;
             }
 
             // Cross-type fully vectorized casting with scales
             const FVec = @Vector(total, f64);
             const float_vec: FVec = switch (comptime @typeInfo(T)) {
-                .float => @floatCast(vec.data),
-                .int => @floatFromInt(vec.data),
+                .float => @floatCast(vec.data.*),
+                .int => @floatFromInt(vec.data.*),
                 else => unreachable,
             };
 
             const scaled = float_vec * @as(FVec, @splat(ratio));
 
-            return switch (comptime @typeInfo(DestT)) {
-                .float => .{ .data = @floatCast(scaled) },
-                .int => .{ .data = @intFromFloat(@round(scaled)) },
+            new.data.* = switch (comptime @typeInfo(DestT)) {
+                .float => @floatCast(scaled),
+                .int => @intFromFloat(@round(scaled)),
                 else => unreachable,
             };
+
+            return new;
         }
 
         const CmpResult = if (total == 1) bool else [total]bool;
@@ -313,7 +332,7 @@ pub fn TensorAlloc(
         }
 
         /// Resolve both sides to the finer scale, broadcasting shape {1} RHS if needed.
-        inline fn resolveScalePair(self: *const Self, rhs: anytype) struct { l: Vec, r: Vec } {
+        inline fn resolveScalePair(self: *const Self, rhs: anytype) struct { l: *Vec, r: *Vec } {
             const RhsType = @TypeOf(rhs);
             if (comptime !isTensor(RhsType))
                 @compileError("rhs can only be a Tensor ");
@@ -622,28 +641,32 @@ pub fn TensorAlloc(
 
 // ─── Scalar tests ─────────────────────────────────────────────────────────
 
-test "Scalar initiat" {
-    const alloc = std.testing.allocator;
+test "TensorAlloc  | Scalar initiat" {
+    var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+    defer arena.deinit();
+    const alloc = arena.allocator();
 
     const Meter = TensorAlloc(i128, .{ .L = 1 }, .{ .L = @enumFromInt(-3) }, &.{1});
     const Second = TensorAlloc(f32, .{ .T = 1 }, .{ .T = .n }, &.{1});
 
     const distance = try Meter.splat(alloc, 10);
-    defer distance.deinit(alloc);
     const time = try Second.splat(alloc, 2);
-    defer time.deinit(alloc);
 
     try std.testing.expectEqual(10, distance.data[0]);
     try std.testing.expectEqual(2, time.data[0]);
 }
 
-// test "Scalar comparisons (eq, ne, gt, gte, lt, lte)" {
+// test "TensorAlloc  | Scalar comparisons (eq, ne, gt, gte, lt, lte)" {
+//     var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+//     defer arena.deinit();
+//     const alloc = arena.allocator();
+//
 //     const Meter = TensorAlloc(i128, .{ .L = 1 }, .{}, &.{1});
 //     const KiloMeter = TensorAlloc(i128, .{ .L = 1 }, .{ .L = .k }, &.{1});
 //
-//     const m1000 = Meter.splat(1000);
-//     const km1 = KiloMeter.splat(1);
-//     const km2 = KiloMeter.splat(2);
+//     const m1000 = try Meter.splat(alloc, 1000);
+//     const km1 = try KiloMeter.splat(alloc, 1);
+//     const km2 = try KiloMeter.splat(alloc, 2);
 //
 //     try std.testing.expect(m1000.eq(km1));
 //     try std.testing.expect(km1.eq(m1000));
@@ -659,30 +682,34 @@ test "Scalar initiat" {
 //     try std.testing.expect(km1.lte(m1000));
 //     try std.testing.expect(m1000.lte(km2));
 // }
-//
-// test "Scalar Add" {
-//     const Meter = TensorAlloc(i128, .{ .L = 1 }, .{}, &.{1});
-//     const KiloMeter = TensorAlloc(i128, .{ .L = 1 }, .{ .L = .k }, &.{1});
-//     const KiloMeter_f = TensorAlloc(f64, .{ .L = 1 }, .{ .L = .k }, &.{1});
-//
-//     const distance = Meter.splat(10);
-//     const distance2 = Meter.splat(20);
-//     const added = distance.add(distance2);
-//     try std.testing.expectEqual(30, added.data[0]);
-//     try std.testing.expectEqual(1, @TypeOf(added).dims.get(.L));
-//
-//     const distance3 = KiloMeter.splat(2);
-//     const added2 = distance.add(distance3);
-//     try std.testing.expectEqual(2010, added2.data[0]);
-//
-//     const added3 = distance3.add(distance).to(KiloMeter);
-//     try std.testing.expectEqual(2, added3.data[0]);
-//
-//     const distance4 = KiloMeter_f.splat(2);
-//     const added4 = distance4.add(distance).to(KiloMeter_f);
-//     try std.testing.expectApproxEqAbs(2.01, added4.data[0], 0.000001);
-// }
-//
+
+test "TensorAlloc  | Scalar Add" {
+    var arena = std.heap.ArenaAllocator.init(std.testing.allocator);
+    defer arena.deinit();
+    const alloc = arena.allocator();
+
+    const Meter = TensorAlloc(i128, .{ .L = 1 }, .{}, &.{1});
+    const KiloMeter = TensorAlloc(i128, .{ .L = 1 }, .{ .L = .k }, &.{1});
+    const KiloMeter_f = TensorAlloc(f64, .{ .L = 1 }, .{ .L = .k }, &.{1});
+
+    const distance = try Meter.splat(alloc, 10);
+    const distance2 = try Meter.splat(alloc, 20);
+    const added = try distance.add(alloc, distance2);
+    try std.testing.expectEqual(30, added.data[0]);
+    try std.testing.expectEqual(1, @TypeOf(added).dims.get(.L));
+
+    const distance3 = try KiloMeter.splat(alloc, 2);
+    const added2 = try distance.add(alloc, distance3);
+    try std.testing.expectEqual(2010, added2.data[0]);
+
+    const added3 = try (try distance3.add(alloc, distance)).to(alloc, KiloMeter);
+    try std.testing.expectEqual(2, added3.data[0]);
+
+    const distance4 = try KiloMeter_f.splat(alloc, 2);
+    const added4 = try (try distance4.add(alloc, distance)).to(alloc, KiloMeter_f);
+    try std.testing.expectApproxEqAbs(2.01, added4.data[0], 0.000001);
+}
+
 // test "Scalar Sub" {
 //     const Meter = TensorAlloc(i128, .{ .L = 1 }, .{}, &.{1});
 //     const KiloMeter_f = TensorAlloc(f64, .{ .L = 1 }, .{ .L = .k }, &.{1});
@@ -1129,3 +1156,70 @@ test "Scalar initiat" {
 //     try std.testing.expectEqual(4, T3.strides_arr[1]);
 //     try std.testing.expectEqual(1, T3.strides_arr[2]);
 // }
+//
+// test "Slice 1D negative start" {
+//     const Vec = TensorStatic(i32, .{}, .{}, &.{5});
+//     const v = Vec{ .data = .{ 10, 20, 30, 40, 50 } };
+//     const s = v.slice(.{.{ .start = -3, .end = 5 }}); // [2,5) → 30,40,50
+//     try std.testing.expectEqual(3, @TypeOf(s).total);
+//     try std.testing.expectEqual(30, s.data[0]);
+//     try std.testing.expectEqual(40, s.data[1]);
+//     try std.testing.expectEqual(50, s.data[2]);
+// }
+//
+// test "Slice 1D negative end" {
+//     const Vec = TensorStatic(i32, .{}, .{}, &.{5});
+//     const v = Vec{ .data = .{ 10, 20, 30, 40, 50 } };
+//     const s = v.slice(.{.{ .start = 1, .end = -1 }}); // [1,4) → 20,30,40
+//     try std.testing.expectEqual(3, @TypeOf(s).total);
+//     try std.testing.expectEqual(20, s.data[0]);
+//     try std.testing.expectEqual(30, s.data[1]);
+//     try std.testing.expectEqual(40, s.data[2]);
+// }
+//
+// test "Slice 1D both negative" {
+//     const Vec = TensorStatic(i64, .{}, .{}, &.{6});
+//     const v = Vec{ .data = .{ 5, 10, 15, 20, 25, 30 } };
+//     const s = v.slice(.{.{ .start = -4, .end = -1 }}); // [2,5) → 15,20,25
+//     try std.testing.expectEqual(3, @TypeOf(s).total);
+//     try std.testing.expectEqual(15, s.data[0]);
+//     try std.testing.expectEqual(20, s.data[1]);
+//     try std.testing.expectEqual(25, s.data[2]);
+// }
+//
+// test "Slice 1D null start" {
+//     const Vec = TensorStatic(i32, .{}, .{}, &.{5});
+//     const v = Vec{ .data = .{ 10, 20, 30, 40, 50 } };
+//     const s = v.slice(.{.{ .end = -2 }}); // [:-2] → 10,20,30
+//     try std.testing.expectEqual(3, @TypeOf(s).total);
+//     try std.testing.expectEqual(10, s.data[0]);
+//     try std.testing.expectEqual(20, s.data[1]);
+//     try std.testing.expectEqual(30, s.data[2]);
+// }
+//
+// test "Slice 1D null end" {
+//     const Vec = TensorStatic(i32, .{}, .{}, &.{5});
+//     const v = Vec{ .data = .{ 10, 20, 30, 40, 50 } };
+//     const s = v.slice(.{.{ .start = -3 }}); // [-3:] → 30,40,50
+//     try std.testing.expectEqual(3, @TypeOf(s).total);
+//     try std.testing.expectEqual(30, s.data[0]);
+//     try std.testing.expectEqual(40, s.data[1]);
+//     try std.testing.expectEqual(50, s.data[2]);
+// }
+//
+// test "Slice 2D negative & null indices" {
+//     const Mat = TensorStatic(i32, .{}, .{}, &.{ 4, 4 });
+//     const m = Mat{ .data = .{
+//         1,  2,  3,  4,
+//         5,  6,  7,  8,
+//         9,  10, 11, 12,
+//         13, 14, 15, 16,
+//     } };
+//     // last 2 rows, last 2 cols → same as subblock test [2,4)x[2,4)
+//     const s = m.slice(.{ .{ .start = -2, .end = 4 }, .{ .start = -2 } });
+//     try std.testing.expectEqual(4, @TypeOf(s).total);
+//     try std.testing.expectEqual(11, s.data[0]);
+//     try std.testing.expectEqual(12, s.data[1]);
+//     try std.testing.expectEqual(15, s.data[2]);
+//     try std.testing.expectEqual(16, s.data[3]);
+// }
diff --git a/src/TensorStatic.zig b/src/TensorStatic.zig
index d63bb47..1e02ff7 100644
--- a/src/TensorStatic.zig
+++ b/src/TensorStatic.zig
@@ -669,7 +669,7 @@ pub fn TensorStatic(
 
 // ─── Scalar tests ─────────────────────────────────────────────────────────
 
-test "Scalar initiat" {
+test "TensorStatic | Scalar initiat" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{ .L = @enumFromInt(-3) }, &.{1});
     const Second = TensorStatic(f32, .{ .T = 1 }, .{ .T = .n }, &.{1});
 
@@ -680,7 +680,7 @@ test "Scalar initiat" {
     try std.testing.expectEqual(2, time.data[0]);
 }
 
-test "Scalar comparisons (eq, ne, gt, gte, lt, lte)" {
+test "TensorStatic | Scalar comparisons (eq, ne, gt, gte, lt, lte)" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{}, &.{1});
     const KiloMeter = TensorStatic(i128, .{ .L = 1 }, .{ .L = .k }, &.{1});
 
@@ -703,7 +703,7 @@ test "Scalar comparisons (eq, ne, gt, gte, lt, lte)" {
     try std.testing.expect(m1000.lte(km2));
 }
 
-test "Scalar Add" {
+test "TensorStatic | Scalar Add" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{}, &.{1});
     const KiloMeter = TensorStatic(i128, .{ .L = 1 }, .{ .L = .k }, &.{1});
     const KiloMeter_f = TensorStatic(f64, .{ .L = 1 }, .{ .L = .k }, &.{1});
@@ -726,7 +726,7 @@ test "Scalar Add" {
     try std.testing.expectApproxEqAbs(2.01, added4.data[0], 0.000001);
 }
 
-test "Scalar Sub" {
+test "TensorStatic | Scalar Sub" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{}, &.{1});
     const KiloMeter_f = TensorStatic(f64, .{ .L = 1 }, .{ .L = .k }, &.{1});
 
@@ -743,7 +743,7 @@ test "Scalar Sub" {
     try std.testing.expectApproxEqAbs(2000, diff3.data[0], 1e-4);
 }
 
-test "Scalar MulBy" {
+test "TensorStatic | Scalar MulBy" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{}, &.{1});
     const Second = TensorStatic(f32, .{ .T = 1 }, .{}, &.{1});
 
@@ -760,7 +760,7 @@ test "Scalar MulBy" {
     try std.testing.expectEqual(2, @TypeOf(area).dims.get(.L));
 }
 
-test "Scalar MulBy with scale" {
+test "TensorStatic | Scalar MulBy with scale" {
     const KiloMeter = TensorStatic(f32, .{ .L = 1 }, .{ .L = .k }, &.{1});
     const KiloGram = TensorStatic(f32, .{ .M = 1 }, .{ .M = .k }, &.{1});
 
@@ -771,7 +771,7 @@ test "Scalar MulBy with scale" {
     try std.testing.expectEqual(1, @TypeOf(prod).dims.get(.M));
 }
 
-test "Scalar MulBy with type change" {
+test "TensorStatic | Scalar MulBy with type change" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{ .L = .k }, &.{1});
     const Second = TensorStatic(f64, .{ .T = 1 }, .{}, &.{1});
     const KmSec = TensorStatic(i64, .{ .L = 1, .T = 1 }, .{ .L = .k }, &.{1});
@@ -784,7 +784,7 @@ test "Scalar MulBy with type change" {
     try std.testing.expectApproxEqAbs(12.0, d.mul(t).to(KmSec_f).data[0], 0.0001);
 }
 
-test "Scalar MulBy small" {
+test "TensorStatic | Scalar MulBy small" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{ .L = .n }, &.{1});
     const Second = TensorStatic(f32, .{ .T = 1 }, .{}, &.{1});
     const d = Meter.splat(3);
@@ -792,7 +792,7 @@ test "Scalar MulBy small" {
     try std.testing.expectEqual(12, d.mul(t).data[0]);
 }
 
-test "Scalar MulBy dimensionless" {
+test "TensorStatic | Scalar MulBy dimensionless" {
     const DimLess = TensorStatic(i128, .{}, .{}, &.{1});
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{}, &.{1});
     const d = Meter.splat(7);
@@ -800,7 +800,7 @@ test "Scalar MulBy dimensionless" {
     try std.testing.expectEqual(21, scaled.data[0]);
 }
 
-test "Scalar Sqrt" {
+test "TensorStatic | Scalar Sqrt" {
     const MeterSquare = TensorStatic(i128, .{ .L = 2 }, .{}, &.{1});
     const MeterSquare_f = TensorStatic(f64, .{ .L = 2 }, .{}, &.{1});
 
@@ -818,7 +818,7 @@ test "Scalar Sqrt" {
     try std.testing.expectApproxEqAbs(4.472135955, scaled2.data[0], 1e-4);
 }
 
-test "Scalar Chained: velocity and acceleration" {
+test "TensorStatic | Scalar Chained: velocity and acceleration" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{}, &.{1});
     const Second = TensorStatic(f32, .{ .T = 1 }, .{}, &.{1});
 
@@ -832,7 +832,7 @@ test "Scalar Chained: velocity and acceleration" {
     try std.testing.expectEqual(5, accel.data[0]);
 }
 
-test "Scalar DivBy integer exact" {
+test "TensorStatic | Scalar DivBy integer exact" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{}, &.{1});
     const Second = TensorStatic(f32, .{ .T = 1 }, .{}, &.{1});
 
@@ -842,7 +842,7 @@ test "Scalar DivBy integer exact" {
     try std.testing.expectEqual(30, vel.data[0]);
 }
 
-test "Scalar Finer scales skip dim 0" {
+test "TensorStatic | Scalar Finer scales skip dim 0" {
     const Dimless = TensorStatic(i128, .{}, .{}, &.{1});
     const KiloMetre = TensorStatic(i128, .{ .L = 1 }, .{ .L = .k }, &.{1});
 
@@ -853,7 +853,7 @@ test "Scalar Finer scales skip dim 0" {
     try std.testing.expectEqual(Scales.UnitScale.k, @TypeOf(vel).scales.get(.L));
 }
 
-test "Scalar Conversion chain: km -> m -> cm" {
+test "TensorStatic | Scalar Conversion chain: km -> m -> cm" {
     const KiloMeter = TensorStatic(i128, .{ .L = 1 }, .{ .L = .k }, &.{1});
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{}, &.{1});
     const CentiMeter = TensorStatic(i128, .{ .L = 1 }, .{ .L = .c }, &.{1});
@@ -865,7 +865,7 @@ test "Scalar Conversion chain: km -> m -> cm" {
     try std.testing.expectEqual(1_500_000, cm.data[0]);
 }
 
-test "Scalar Conversion: hours -> minutes -> seconds" {
+test "TensorStatic | Scalar Conversion: hours -> minutes -> seconds" {
     const Hour = TensorStatic(i128, .{ .T = 1 }, .{ .T = .hour }, &.{1});
     const Minute = TensorStatic(i128, .{ .T = 1 }, .{ .T = .min }, &.{1});
     const Second = TensorStatic(i128, .{ .T = 1 }, .{}, &.{1});
@@ -877,7 +877,7 @@ test "Scalar Conversion: hours -> minutes -> seconds" {
     try std.testing.expectEqual(3600, sec.data[0]);
 }
 
-test "Scalar Format" {
+test "TensorStatic | Scalar Format" {
     const MeterPerSecondSq = TensorStatic(f32, .{ .L = 1, .T = -2 }, .{ .T = .n }, &.{1});
     const Meter = TensorStatic(f32, .{ .L = 1 }, .{}, &.{1});
 
@@ -892,7 +892,7 @@ test "Scalar Format" {
     try std.testing.expectEqualStrings("9.81m.ns⁻²", res);
 }
 
-test "Scalar Abs" {
+test "TensorStatic | Scalar Abs" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{}, &.{1});
     const MeterF = TensorStatic(f32, .{ .L = 1 }, .{}, &.{1});
 
@@ -900,21 +900,21 @@ test "Scalar Abs" {
     try std.testing.expectEqual(42.5, MeterF.splat(-42.5).abs().data[0]);
 }
 
-test "Scalar Pow" {
+test "TensorStatic | Scalar Pow" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{}, &.{1});
     const d = Meter.splat(4);
     try std.testing.expectEqual(16, d.pow(2).data[0]);
     try std.testing.expectEqual(64, d.pow(3).data[0]);
 }
 
-test "Scalar add/sub bare number on dimensionless scalar" {
+test "TensorStatic | Scalar add/sub bare number on dimensionless scalar" {
     const DimLess = TensorStatic(i128, .{}, .{}, &.{1});
     const a = DimLess.splat(10);
     try std.testing.expectEqual(15, a.add(DimLess.splat(5)).data[0]);
     try std.testing.expectEqual(7, a.sub(DimLess.splat(3)).data[0]);
 }
 
-test "Scalar Imperial length scales" {
+test "TensorStatic | Scalar Imperial length scales" {
     const Foot = TensorStatic(f64, .{ .L = 1 }, .{ .L = .ft }, &.{1});
     const Meter = TensorStatic(f64, .{ .L = 1 }, .{}, &.{1});
     const Inch = TensorStatic(f64, .{ .L = 1 }, .{ .L = .inch }, &.{1});
@@ -923,7 +923,7 @@ test "Scalar Imperial length scales" {
     try std.testing.expectApproxEqAbs(1.0, Inch.splat(12.0).to(Foot).data[0], 1e-9);
 }
 
-test "Scalar Imperial mass scales" {
+test "TensorStatic | Scalar Imperial mass scales" {
     const Pound = TensorStatic(f64, .{ .M = 1 }, .{ .M = .lb }, &.{1});
     const Ounce = TensorStatic(f64, .{ .M = 1 }, .{ .M = .oz }, &.{1});
 
@@ -933,14 +933,14 @@ test "Scalar Imperial mass scales" {
 
 // ─── Vector / Tensor tests ────────────────────────────────────────────────
 
-test "Vector initiate" {
+test "TensorStatic | Vector initiate" {
     const Meter4 = TensorStatic(f32, .{ .L = 1 }, .{}, &.{4});
     const m = Meter4.splat(1);
     try std.testing.expect(m.data[0] == 1);
     try std.testing.expect(m.data[3] == 1);
 }
 
-test "Vector format" {
+test "TensorStatic | Vector format" {
     const MeterPerSecondSq = TensorStatic(f32, .{ .L = 1, .T = -2 }, .{ .T = .n }, &.{3});
     const KgMeterPerSecond = TensorStatic(f32, .{ .M = 1, .L = 1, .T = -1 }, .{ .M = .k }, &.{3});
 
@@ -955,7 +955,7 @@ test "Vector format" {
     try std.testing.expectEqualStrings("(43.00, 0.00, 11.00)m.kg.s⁻¹", res);
 }
 
-test "Vector Vec3 Init and Basic Arithmetic" {
+test "TensorStatic | Vector Vec3 Init and Basic Arithmetic" {
     const Meter3 = TensorStatic(i32, .{ .L = 1 }, .{}, &.{3});
 
     const v_zero = Meter3.zero;
@@ -987,7 +987,7 @@ test "Vector Vec3 Init and Basic Arithmetic" {
     try std.testing.expectEqual(-30, neg.data[2]);
 }
 
-test "Vector Kinematics (scalar mul/div broadcast)" {
+test "TensorStatic | Vector Kinematics (scalar mul/div broadcast)" {
     const Meter3 = TensorStatic(i32, .{ .L = 1 }, .{}, &.{3});
     const Second1 = TensorStatic(i32, .{ .T = 1 }, .{}, &.{1});
 
@@ -1006,7 +1006,7 @@ test "Vector Kinematics (scalar mul/div broadcast)" {
     try std.testing.expectEqual(0, @TypeOf(new_pos).dims.get(.T));
 }
 
-test "Vector Element-wise Math and Scaling" {
+test "TensorStatic | Vector Element-wise Math and Scaling" {
     const Meter3 = TensorStatic(i32, .{ .L = 1 }, .{}, &.{3});
 
     const v1 = Meter3{ .data = .{ 10, 20, 30 } };
@@ -1018,7 +1018,7 @@ test "Vector Element-wise Math and Scaling" {
     try std.testing.expectEqual(0, @TypeOf(dv).dims.get(.L));
 }
 
-test "Vector Conversions" {
+test "TensorStatic | Vector Conversions" {
     const KiloMeter3 = TensorStatic(i32, .{ .L = 1 }, .{ .L = .k }, &.{3});
     const Meter3 = TensorStatic(i32, .{ .L = 1 }, .{}, &.{3});
 
@@ -1030,7 +1030,7 @@ test "Vector Conversions" {
     try std.testing.expectEqual(UnitScale.none, @TypeOf(v_m).scales.get(.L));
 }
 
-test "Vector Length" {
+test "TensorStatic | Vector Length" {
     const MeterInt3 = TensorStatic(i32, .{ .L = 1 }, .{}, &.{3});
     const MeterFloat3 = TensorStatic(f32, .{ .L = 1 }, .{}, &.{3});
 
@@ -1043,7 +1043,7 @@ test "Vector Length" {
     try std.testing.expectApproxEqAbs(@as(f32, 5.0), v_float.length(), 1e-4);
 }
 
-test "Vector Comparisons" {
+test "TensorStatic | Vector Comparisons" {
     const Meter3 = TensorStatic(f32, .{ .L = 1 }, .{}, &.{3});
     const KiloMeter3 = TensorStatic(f32, .{ .L = 1 }, .{ .L = .k }, &.{3});
 
@@ -1068,7 +1068,7 @@ test "Vector Comparisons" {
     try std.testing.expect(low_eq[0] and low_eq[1] and low_eq[2]);
 }
 
-test "Vector vs Scalar broadcast comparison" {
+test "TensorStatic | Vector vs Scalar broadcast comparison" {
     const Meter3 = TensorStatic(f32, .{ .L = 1 }, .{}, &.{3});
     const KiloMeter1 = TensorStatic(f32, .{ .L = 1 }, .{ .L = .k }, &.{1});
 
@@ -1086,7 +1086,7 @@ test "Vector vs Scalar broadcast comparison" {
     try std.testing.expect(exact[1] == false);
 }
 
-test "Vector contract — dot product (rank-1 * rank-1)" {
+test "TensorStatic | Vector contract — dot product (rank-1 * rank-1)" {
     const Meter3 = TensorStatic(f32, .{ .L = 1 }, .{}, &.{3});
     const Newton3 = TensorStatic(f32, .{ .M = 1, .L = 1, .T = -2 }, .{}, &.{3});
 
@@ -1100,7 +1100,7 @@ test "Vector contract — dot product (rank-1 * rank-1)" {
     try std.testing.expectEqual(-2, @TypeOf(work).dims.get(.T));
 }
 
-test "Vector contract — matrix multiply (rank-2 * rank-2)" {
+test "TensorStatic | Vector contract — matrix multiply (rank-2 * rank-2)" {
     const A = TensorStatic(f32, .{}, .{}, &.{ 2, 3 });
     const B = TensorStatic(f32, .{}, .{}, &.{ 3, 2 });
 
@@ -1114,7 +1114,7 @@ test "Vector contract — matrix multiply (rank-2 * rank-2)" {
     try std.testing.expectEqual(154, c.data[TensorStatic(f32, .{}, .{}, &.{ 2, 2 }).idx(.{ 1, 1 })]);
 }
 
-test "Vector Abs, Pow, Sqrt and Product" {
+test "TensorStatic | Vector Abs, Pow, Sqrt and Product" {
     const Meter3 = TensorStatic(f32, .{ .L = 1 }, .{}, &.{3});
 
     const v1 = Meter3{ .data = .{ -2.0, 3.0, -4.0 } };
@@ -1137,7 +1137,7 @@ test "Vector Abs, Pow, Sqrt and Product" {
     try std.testing.expectEqual(1, @TypeOf(sqrted).dims.get(.L));
 }
 
-test "Vector eq broadcast on dimensionless" {
+test "TensorStatic | Vector eq broadcast on dimensionless" {
     const DimLess3 = TensorStatic(i32, .{}, .{}, &.{3});
     const v = DimLess3{ .data = .{ 1, 2, 3 } };
 
@@ -1147,7 +1147,7 @@ test "Vector eq broadcast on dimensionless" {
     try std.testing.expectEqual(false, eq_res[2]);
 }
 
-test "Tensor idx helper and matrix access" {
+test "TensorStatic | Tensor idx helper and matrix access" {
     const Mat3x3 = TensorStatic(f32, .{}, .{}, &.{ 3, 3 });
     var m: Mat3x3 = Mat3x3.zero;
     m.data[Mat3x3.idx(.{ 0, 0 })] = 1.0;
@@ -1160,7 +1160,7 @@ test "Tensor idx helper and matrix access" {
     try std.testing.expectEqual(0.0, m.data[1]);
 }
 
-test "Tensor strides_arr correctness" {
+test "TensorStatic | Tensor strides_arr correctness" {
     const T1 = TensorStatic(f32, .{}, .{}, &.{3});
     const T2 = TensorStatic(f32, .{}, .{}, &.{ 3, 4 });
     const T3 = TensorStatic(f32, .{}, .{}, &.{ 2, 3, 4 });
@@ -1173,7 +1173,7 @@ test "Tensor strides_arr correctness" {
     try std.testing.expectEqual(1, T3.strides_arr[2]);
 }
 
-test "Slice 1D basic" {
+test "TensorStatic | Slice 1D basic" {
     const Vec = TensorStatic(i32, .{}, .{}, &.{5});
     var v = Vec{ .data = .{ 10, 20, 30, 40, 50 } };
     const s = v.slice(.{.{ .start = 1, .end = 4 }});
@@ -1183,7 +1183,7 @@ test "Slice 1D basic" {
     try std.testing.expectEqual(40, s.data[2]);
 }
 
-test "Slice 1D full range" {
+test "TensorStatic | Slice 1D full range" {
     const Vec = TensorStatic(f32, .{}, .{}, &.{4});
     const v = Vec{ .data = .{ 1.0, 2.0, 3.0, 4.0 } };
     const s = v.slice(.{.{ .start = 0, .end = 4 }});
@@ -1191,7 +1191,7 @@ test "Slice 1D full range" {
     inline for (0..4) |i| try std.testing.expectEqual(v.data[i], s.data[i]);
 }
 
-test "Slice 1D single element" {
+test "TensorStatic | Slice 1D single element" {
     const Vec = TensorStatic(i64, .{}, .{}, &.{6});
     const v = Vec{ .data = .{ 5, 10, 15, 20, 25, 30 } };
     const s = v.slice(.{.{ .start = 3, .end = 4 }});
@@ -1199,7 +1199,7 @@ test "Slice 1D single element" {
     try std.testing.expectEqual(20, s.data[0]);
 }
 
-test "Slice 1D preserves dims and scales" {
+test "TensorStatic | Slice 1D preserves dims and scales" {
     const Meter = TensorStatic(i128, .{ .L = 1 }, .{ .L = .k }, &.{5});
     const v = Meter{ .data = .{ 1, 2, 3, 4, 5 } };
     const s = v.slice(.{.{ .start = 0, .end = 3 }});
@@ -1208,7 +1208,7 @@ test "Slice 1D preserves dims and scales" {
     try std.testing.expectEqual(Meter.scales.get(.L), S.scales.get(.L));
 }
 
-test "Slice 2D rows" {
+test "TensorStatic | Slice 2D rows" {
     const Mat = TensorStatic(i32, .{}, .{}, &.{ 4, 3 });
     const m = Mat{ .data = .{
         1,  2,  3,
@@ -1227,7 +1227,7 @@ test "Slice 2D rows" {
     try std.testing.expectEqual(9, s.data[5]);
 }
 
-test "Slice 2D cols" {
+test "TensorStatic | Slice 2D cols" {
     const Mat = TensorStatic(i32, .{}, .{}, &.{ 3, 4 });
     const m = Mat{ .data = .{
         1, 2,  3,  4,
@@ -1247,7 +1247,7 @@ test "Slice 2D cols" {
     try std.testing.expectEqual(11, s.data[5]);
 }
 
-test "Slice 2D subblock" {
+test "TensorStatic | Slice 2D subblock" {
     const Mat = TensorStatic(f64, .{}, .{}, &.{ 4, 4 });
     const m = Mat{ .data = .{
         1,  2,  3,  4,
@@ -1264,7 +1264,7 @@ test "Slice 2D subblock" {
     try std.testing.expectApproxEqAbs(11.0, s.data[3], 1e-9);
 }
 
-test "Slice then add" {
+test "TensorStatic | Slice then add" {
     const Meter = TensorStatic(i32, .{ .L = 1 }, .{}, &.{5});
     const a = Meter{ .data = .{ 1, 2, 3, 4, 5 } };
     const b = Meter{ .data = .{ 10, 20, 30, 40, 50 } };
@@ -1276,7 +1276,7 @@ test "Slice then add" {
     try std.testing.expectEqual(53, r.data[2]); // 3+50
 }
 
-test "Slice then scale convert" {
+test "TensorStatic | Slice then scale convert" {
     const KiloMeter = TensorStatic(i64, .{ .L = 1 }, .{ .L = .k }, &.{4});
     const Meter = TensorStatic(i64, .{ .L = 1 }, .{}, &.{2});
     const v = KiloMeter{ .data = .{ 1, 2, 3, 4 } };
@@ -1286,7 +1286,7 @@ test "Slice then scale convert" {
     try std.testing.expectEqual(3000, converted.data[1]);
 }
 
-test "Slice 1D negative start" {
+test "TensorStatic | Slice 1D negative start" {
     const Vec = TensorStatic(i32, .{}, .{}, &.{5});
     const v = Vec{ .data = .{ 10, 20, 30, 40, 50 } };
     const s = v.slice(.{.{ .start = -3, .end = 5 }}); // [2,5) → 30,40,50
@@ -1296,7 +1296,7 @@ test "Slice 1D negative start" {
     try std.testing.expectEqual(50, s.data[2]);
 }
 
-test "Slice 1D negative end" {
+test "TensorStatic | Slice 1D negative end" {
     const Vec = TensorStatic(i32, .{}, .{}, &.{5});
     const v = Vec{ .data = .{ 10, 20, 30, 40, 50 } };
     const s = v.slice(.{.{ .start = 1, .end = -1 }}); // [1,4) → 20,30,40
@@ -1306,7 +1306,7 @@ test "Slice 1D negative end" {
     try std.testing.expectEqual(40, s.data[2]);
 }
 
-test "Slice 1D both negative" {
+test "TensorStatic | Slice 1D both negative" {
     const Vec = TensorStatic(i64, .{}, .{}, &.{6});
     const v = Vec{ .data = .{ 5, 10, 15, 20, 25, 30 } };
     const s = v.slice(.{.{ .start = -4, .end = -1 }}); // [2,5) → 15,20,25
@@ -1316,7 +1316,7 @@ test "Slice 1D both negative" {
     try std.testing.expectEqual(25, s.data[2]);
 }
 
-test "Slice 1D null start" {
+test "TensorStatic | Slice 1D null start" {
     const Vec = TensorStatic(i32, .{}, .{}, &.{5});
     const v = Vec{ .data = .{ 10, 20, 30, 40, 50 } };
     const s = v.slice(.{.{ .end = -2 }}); // [:-2] → 10,20,30
@@ -1326,7 +1326,7 @@ test "Slice 1D null start" {
     try std.testing.expectEqual(30, s.data[2]);
 }
 
-test "Slice 1D null end" {
+test "TensorStatic | Slice 1D null end" {
     const Vec = TensorStatic(i32, .{}, .{}, &.{5});
     const v = Vec{ .data = .{ 10, 20, 30, 40, 50 } };
     const s = v.slice(.{.{ .start = -3 }}); // [-3:] → 30,40,50
@@ -1336,7 +1336,7 @@ test "Slice 1D null end" {
     try std.testing.expectEqual(50, s.data[2]);
 }
 
-test "Slice 2D negative & null indices" {
+test "TensorStatic | Slice 2D negative & null indices" {
     const Mat = TensorStatic(i32, .{}, .{}, &.{ 4, 4 });
     const m = Mat{ .data = .{
         1,  2,  3,  4,