690.lean:3:2-3:29: error: too many variable names provided at alternative 'step', #3 provided, but #2 expected
690.lean:6:0-6:7: warning: declaration uses 'sorry'
case step
a b m✝ : Nat
hStep : Nat.le a m✝
ih : Nat.le a (m✝ + 1)
⊢ Nat.le a (Nat.succ m✝ + 1)
690.lean:11:0-11:7: warning: declaration uses 'sorry'
case step
a b x : Nat
hStep : Nat.le a x
ih : Nat.le a (x + 1)
⊢ Nat.le a (Nat.succ x + 1)