lean4-htt/tests/lean/run/eq17.lean
2016-09-20 08:32:37 -07:00

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Text

open nat
attribute [pattern] lt.base
attribute [pattern] lt.step
definition lt_of_succ {a : nat} : ∀ {b : nat}, succ a < b → a < b
| .(succ (succ a)) (lt.base .(succ a)) := nat.lt_trans (lt.base a) (lt.base (succ a))
| .(succ b) (@lt.step .(succ a) b h) := lt.step (lt_of_succ h)