Theorem: Set.insert_union_right (GMLInit/Data/Set/Insert.lean)

State before:
α : Sort u_1
a : α
s t : Set α
⊢ s.union (t.insert a) = (s.union (Set.pure a)).union t
Tactic:
rw [union_assoc]
State after:
no goals

State before:
α : Sort u_1
a : α
s t : Set α
⊢ (s.union (Set.pure a)).union t = ((Set.pure a).union s).union t
Tactic:
rw [union_comm (Set.pure a) s]
State after:
no goals

State before:
α : Sort u_1
a : α
s t : Set α
⊢ ((Set.pure a).union s).union t = (Set.pure a).union (s.union t)
Tactic:
rw [union_assoc]
State after:
no goals