Theorem lmemmapi | index | src |

theorem lmemmapi (F: set) (a l: nat): $ a IN l -> F @ a IN map F l $;
StepHypRefExpression
1 lmemnth
a IN l <-> E. a1 nth a1 l = suc a
2 nthlmem
nth a1 (map F l) = suc (F @ a) -> F @ a IN map F l
3 mapnth
nth a1 l = suc a -> nth a1 (map F l) = suc (F @ a)
4 2, 3 syl
nth a1 l = suc a -> F @ a IN map F l
5 4 eex
E. a1 nth a1 l = suc a -> F @ a IN map F l
6 1, 5 sylbi
a IN l -> F @ a IN map F l

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 (peano1, peano2, peano5, addeq, muleq, add0, addS, mul0, mulS)