Theorem exanal | index | src |

theorem exanal {x: nat} (a b: wff x): $ E. x a /\ A. x b -> E. x (a /\ b) $;
StepHypRefExpression
1 exim
A. x (a -> a /\ b) -> E. x a -> E. x (a /\ b)
2 ian
a -> b -> a /\ b
3 2 com12
b -> a -> a /\ b
4 3 alimi
A. x b -> A. x (a -> a /\ b)
5 1, 4 syl
A. x b -> E. x a -> E. x (a /\ b)
6 5 impcom
E. x a /\ A. x b -> E. x (a /\ b)

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp), axs_pred_calc (ax_gen, ax_4)