begin_end_bug.lean:3:24: error: unknown identifier 'a'
begin_end_bug.lean:3:18: error: don't know how to synthesize placeholder
context:
a b c : ℕ,
hab : a = b,
hac : a = c
⊢ Type
begin_end_bug.lean:3:48: error: _interaction._lambda_3: trying to evaluate sorry