open tactic

example (p q : Prop) : p → q → p ∧ q :=
by do intros, constructor, assumption, assumption

example (p q : Prop) : p → q → p ∧ q :=
by do intros, split, assumption, assumption

example (p q : Prop) : p → p ∨ q :=
by do intros, left, assumption

example (p q : Prop) : q → p ∨ q :=
by do intros, right, assumption

example (p q : Prop) : p → p ∨ q :=
by do intros, constructor_idx 1, assumption

example (p q : Prop) : q → p ∨ q :=
by do intros, constructor_idx 2, assumption

example (a : nat) : a = a :=
by constructor

example (a b : nat) : ∃ x, x = a :=
by do
  a ← get_local `a,
  existsi a,
  trace_state,
  constructor