lean4-htt/tests/lean/run/ack.lean
Leonardo de Moura 98864f707e test: add test for #879
The new `termination_by` syntax should address issue #879

closes #879
2022-01-12 16:25:09 -08:00

5 lines
141 B
Text

def ack : Nat → Nat → Nat
| 0, y => y+1
| x+1, 0 => ack x 1
| x+1, y+1 => ack x (ack (x+1) y)
termination_by _ a b => (a, b)