first goal
p q : Prop,
a : p,
a_1 : q
⊢ p ∧ p
--- Second goal: 
p q : Prop,
a : p,
a_1 : q
⊢ q
--- After
p q : Prop,
a : p,
a_1 : q
⊢ p

p q : Prop,
a : p,
a_1 : q
⊢ p
should not work
should not work
should work