kernel-Nat.coprime_div_left
- Kind
- kernel-term
- Status
- checked
Supports: The proposition declared as `Nat.Coprime.coprime_div_left` in the pinned Mathlib v4.30 source.
cargo test -p axeyum-lean-kernel --lib nat_prelude:: Evidence notes
`Nat.coprime_div_left` in `crates/axeyum-lean-kernel/src/nat_prelude/coprime_lemmas.rs (declare_coprime_div_left)`. Mirror image of `Nat.coprime_div_right`: cases on the divisor `a`, dividing `m` instead of `n`. At `a = 0`, `dvd 0 m` forces `m = 0` (`zero_mul`) and `div _ 0 = 0` (`div_zero`) collapse both sides; at `a = succ a'`, the witness from `dvd a m` recovers `div m a` via `div_mul_cancel_of_dvd`, and the succ-branch shrink step uses `coprime_of_dvd_left` (shrinking the LEFT `gcd` argument) instead of `coprime_of_dvd_right`. Pinned by a concrete-instantiation test exercising both branches (`nat_prelude_tests::coprime_div_left_applies_at_both_branches_of_its_case_split`).