4. Semantics and Graphs
This section explains the objects that TorchLean claims are about.
The spec layer gives mathematical meanings to tensors, layers, losses, masks, modes, and scalar
choices. GraphSpec gives a typed architecture language for models whose parameter layout and
sharing structure should be explicit. NN.IR.Graph gives the operation-tagged graph consumed by
widgets, exporters, runtime bridges, and verification passes.
These layers are connected, but they are not interchangeable. A spec definition is a mathematical reference. A GraphSpec model is an architecture with a typed parameter interface. An IR graph is a low-level artifact with op tags, parent ids, shapes, and payloads. Keeping those roles separate is what lets TorchLean say exactly what a runtime, compiler, or verifier has checked.