English
If reduce L1 = reduce L2, then mk L1 = mk L2.
Русский
Если reduce L1 = reduce L2, то mk L1 = mk L2.
LaTeX
$$$$\operatorname{reduce}(L_1) = \operatorname{reduce}(L_2) \Rightarrow \operatorname{mk}L_1 = \operatorname{mk}L_2.$$$$
Lean4
/-- If two words have a common maximal reduction, then they correspond to the same element in the
free group. -/
@[to_additive /-- If two words have a common maximal reduction, then they correspond to the same
element in the additive free group. -/
]
theorem exact (H : reduce L₁ = reduce L₂) : mk L₁ = mk L₂ :=
Red.exact.2 ⟨reduce L₂, H ▸ reduce.red, reduce.red⟩