Theorem bgcdpos | index | src |

theorem bgcdpos (a b: nat): $ a != 0 -> 0 < bgcd a b $;
StepHypRefExpression
1 bgcdlem
a != 0 -> 0 < bgcd a b /\ E. x E. y x * a = y * b + bgcd a b
2 1 anld
a != 0 -> 0 < bgcd a 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_set (elab, ax_8), axs_the (theid), axs_peano (peano1, peano2, peano5, addeq, muleq, add0, addS, mul0, mulS)