Theorem znegneg | index | src |

theorem znegneg (n: nat): $ -uZ -uZ n = n $;
StepHypRefExpression
1 eqtr
-uZ -uZ n = zfst n -ZN zsnd n -> zfst n -ZN zsnd n = n -> -uZ -uZ n = n
2 znegzn
-uZ (zsnd n -ZN zfst n) = zfst n -ZN zsnd n
3 2 conv zneg
-uZ -uZ n = zfst n -ZN zsnd n
4 1, 3 ax_mp
zfst n -ZN zsnd n = n -> -uZ -uZ n = n
5 zfstsnd
zfst n -ZN zsnd n = n
6 4, 5 ax_mp
-uZ -uZ n = n

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)