a b c : Int
h✝ : -b + a < c
h : b + (-b + a) < b + c
⊢ a < b + c
a b c : Int
h : -b + a < c
⊢ a < b + c
have h := Int.add_lt_add_left h b
no goals
a b c : Int
h✝ : -b + a < c
h : b + (-b + a) < b + c
⊢ a < b + c
rwa [Int.add_neg_cancel_left] at h