User developments often use stdlib functions with inputs whose natural equivalence relation does not coincide with Logc.eq: most importantly functions, but also Q, non-hprop sigma types, etc. Then they eventually need the fact that (forall x y, x = y -> f x = g y) -> stdlibfunc f a = stdlibfunc g a. stdlib should make lemmas of this form easily accessible, ideally in a systematic auto-generated form.
User developments often use stdlib functions with inputs whose natural equivalence relation does not coincide with
Logc.eq: most importantly functions, but alsoQ, non-hpropsigma types, etc. Then they eventually need the fact that(forall x y, x = y -> f x = g y) -> stdlibfunc f a = stdlibfunc g a. stdlib should make lemmas of this form easily accessible, ideally in a systematic auto-generated form.