Theorem Arrowisf ≪ | index | src | ≫

theorem Arrowisf (A B: set) (f: nat): $ f e. Arrow A B -> isfun f $;

Step	Hyp	Ref	Expression
1		elArrow	f e. Arrow A B <-> func f A B
2		funcisf	func f A B -> isfun f
3	1, 2	sylbi	f e. Arrow A B -> isfun f

Axiom use

axs_prop_calc (ax_1, ax_2, ax_3, ax_mp, itru), axs_pred_calc (ax_gen, ax_4, ax_5, ax_6, ax_7, ax_10, ax_11, ax_12), axs_set (elab, ax_8), axs_the (theid, the0), axs_peano (peano2, addeq, muleq)