Theorem eqs_refl | index | src |

集合等号自反性

theorem eqs_refl (x: set): $ x = x $;
StepHypRefExpression
1 fo_imp_inslsto_ex_absrs
\fo y (y = x \imp x = x) \imp \ex y y = x \imp x = x
2 imp_imp_assiml
(y = x \imp y = x \imp x = x) \imp y = x \imp x = x
3 equality
y = x \imp y = x \imp x = x
4 2, 3 ax_mp
y = x \imp x = x
5 4 intro_fo
\fo y (y = x \imp x = x)
6 1, 5 ax_mp
\ex y y = x \imp x = x
7 existene
\ex y y = x
8 6, 7 ax_mp
x = x

Axiom use

Logic (ax_mp, ax_1, ax_2, ax_3, ax_gen, ax_4, ax_5, ax_6, ax_7)