lean4-htt/doc/examples/NFM2022/nfm17.lean
2022-05-23 18:20:37 -07:00

19 lines
356 B
Text

/- More tactics -/
example (p q : Nat → Prop) : (∃ x, p x ∧ q x) → ∃ x, q x ∧ p x := by
intro h
cases h with
| intro x hpq =>
cases hpq with
| intro hp hq =>
exists x
example : p ∧ q → q ∧ p := by
intro p
cases p
constructor <;> assumption
example : p ∧ ¬ p → q := by
intro h
cases h
contradiction