Theorem mulrass | index | src |

theorem mulrass (a b c: nat): $ a * b * c = a * c * b $;
StepHypRefExpression
1 eqtr
a * b * c = a * (b * c) -> a * (b * c) = a * c * b -> a * b * c = a * c * b
2 mulass
a * b * c = a * (b * c)
3 1, 2 ax_mp
a * (b * c) = a * c * b -> a * b * c = a * c * b
4 eqtr4
a * (b * c) = a * (c * b) -> a * c * b = a * (c * b) -> a * (b * c) = a * c * b
5 muleq2
b * c = c * b -> a * (b * c) = a * (c * b)
6 mulcom
b * c = c * b
7 5, 6 ax_mp
a * (b * c) = a * (c * b)
8 4, 7 ax_mp
a * c * b = a * (c * b) -> a * (b * c) = a * c * b
9 mulass
a * c * b = a * (c * b)
10 8, 9 ax_mp
a * (b * c) = a * c * b
11 3, 10 ax_mp
a * b * c = a * c * b

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