Module contract 

Multi-tensor contraction with optimal contraction order.

This module provides functions to contract multiple tensors efficiently using einsum optimization via the tensorbackend (tenferro-backed implementation).

This module works with concrete types (DynIndex, TensorDynLen) only.

Main Functions

• contract: Contracts one connected tensor network
• contract_with_options: Contracts one connected tensor network with retained indices

Diag Tensor Handling

Diagonal tensors are materialized as dense native operands for contraction, so numeric einsum labels must keep uncontracted logical axes distinct. Diagonal/structured equality metadata is propagated separately onto the result when the contraction leaves equal axes behind.

Structs

AxisUnionFind

Union-Find data structure for grouping axis IDs.

ContractionOptions

Options for multi-tensor contraction.

PairwiseContractionOptions

Options for pairwise tensor contraction.

Functions

build_diag_union

Build a union-find structure from a collection of tensors.

collect_sizes

Collect dimension sizes for remapped IDs.

contract

Contract a connected tensor network with the default semantics.

contract_owned

Contract owned tensors with the default connected-network semantics.

contract_owned_with_options

Contract owned tensors with advanced connected-network options.

contract_pair

Contract two tensors with the default pairwise semantics.

contract_pair_with_operand_options

Contract two tensors with operand-level conjugation options.

contract_pair_with_options

Contract two tensors with explicit contraction options.

contract_with_options

Contract a connected tensor network with advanced options.

outer_product

Compute the outer product of two tensors.

print_and_reset_contract_profile

Print and clear the aggregated multi-tensor contraction profile.

remap_output_ids

Remap output IDs using the union-find structure.

remap_tensor_ids

Remap tensor indices using the union-find structure.

reset_contract_profile

Reset the aggregated multi-tensor contraction profile.

tensordot

Contract two tensors along explicitly specified index pairs.