new structural witness type (#22)

* new structural witness type

* misc: cleanup length_instance_id

* chores: docs

tracing instrument to level trace (#21)

add biguint api (#20)

biguint api (#19)

rotation support (#18)

expression to dag nodes (#17)

* expression to arithmetics

* return max degree and depth

* simplify api

* dedup constant & challenge

* Dag in node structure

* with zero/one optimisation

* build dag from monomial terms

* tune api interface

* chores: rename & clippy

* fmt

new expression api (#15)

* new expression api

* chores: clippy

* fmt

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Co-authored-by: kunxian xia <xiakunxian130@gmail.com>

feat: add new permutation-related APIs (#13)

* impl Default for SwCurves

* Self::P is an permutation of Ts

* add get_default_perm_rc

* revert defaults

* clippy

Add transformation utility functions between biguint and words. (#14)

Add biguint <-> words

chore: make `p3-poseidon2-air` public (#12)

* make p3-poseidon2-air public

* taplo fmt

* make p3-air public

* make p3-monty-31 public