Theorem onnmin 4478

Description: No member of a set of ordinal numbers belongs to its minimum. (Contributed by NM, 2-Feb-1997.) (Constructive proof by Mario Carneiro and Jim Kingdon, 21-Jul-2019.)

Assertion

Ref	Expression
onnmin	|- ( ( A C_ On /\ B e. A ) -> -. B e. |^| A )

Proof of Theorem onnmin

Step	Hyp	Ref	Expression
1		intss1 3781	. . 3 |- ( B e. A -> |^| A C_ B )
2		elirr 4451	. . . 4 |- -. B e. B
3		ssel 3086	. . . 4 |- ( |^| A C_ B -> ( B e. |^| A -> B e. B ) )
4	2, 3	mtoi 653	. . 3 |- ( |^| A C_ B -> -. B e. |^| A )
5	1, 4	syl 14	. 2 |- ( B e. A -> -. B e. |^| A )
6	5	adantl 275	1 |- ( ( A C_ On /\ B e. A ) -> -. B e. |^| A )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 103   e. wcel 1480   C_ wss 3066   |^|cint 3766   Oncon0 4280

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 603  ax-in2 604  ax-io 698  ax-5 1423  ax-7 1424  ax-gen 1425  ax-ie1 1469  ax-ie2 1470  ax-8 1482  ax-10 1483  ax-11 1484  ax-i12 1485  ax-bndl 1486  ax-4 1487  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515  ax-ext 2119  ax-setind 4447

This theorem depends on definitions:  df-bi 116  df-3an 964  df-tru 1334  df-nf 1437  df-sb 1736  df-clab 2124  df-cleq 2130  df-clel 2133  df-nfc 2268  df-ne 2307  df-ral 2419  df-v 2683  df-dif 3068  df-in 3072  df-ss 3079  df-sn 3528  df-int 3767

This theorem is referenced by: (None)