x : Nat
a : A (x + 0)
⊢ f x a = x
simp_dsimp.lean:4:0-4:7: warning: declaration uses `sorry`
x : Nat
a : A (x + 0)
⊢ f (x + 0) a = x
simp_dsimp.lean:9:0-9:7: warning: declaration uses `sorry`