Theorem iniseg 4976

Description: An idiom that signifies an initial segment of an ordering, used, for example, in Definition 6.21 of [TakeutiZaring] p. 30. (Contributed by NM, 28-Apr-2004.)

Assertion

Ref	Expression
iniseg	|- ( B e. V -> ( `' A " { B } ) = { x | x A B } )

Distinct variable groups:   x, A   x, B

Allowed substitution hint:   V( x)

Proof of Theorem iniseg

Step	Hyp	Ref	Expression
1		elex 2737	. 2 |- ( B e. V -> B e. _V )
2		vex 2729	. . . 4 |- x e. _V
3	2	eliniseg 4974	. . 3 |- ( B e. _V -> ( x e. ( `' A " { B } ) <-> x A B ) )
4	3	abbi2dv 2285	. 2 |- ( B e. _V -> ( `' A " { B } ) = { x | x A B } )
5	1, 4	syl 14	1 |- ( B e. V -> ( `' A " { B } ) = { x | x A B } )

Syntax hints:   -> wi 4   = wceq 1343   e. wcel 2136   {cab 2151   _Vcvv 2726   {csn 3576   class class class wbr 3982   `'ccnv 4603   "cima 4607

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-io 699  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-14 2139  ax-ext 2147  ax-sep 4100  ax-pow 4153  ax-pr 4187

This theorem depends on definitions:  df-bi 116  df-3an 970  df-tru 1346  df-nf 1449  df-sb 1751  df-eu 2017  df-mo 2018  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-ral 2449  df-rex 2450  df-v 2728  df-sbc 2952  df-un 3120  df-in 3122  df-ss 3129  df-pw 3561  df-sn 3582  df-pr 3583  df-op 3585  df-br 3983  df-opab 4044  df-xp 4610  df-cnv 4612  df-dm 4614  df-rn 4615  df-res 4616  df-ima 4617

This theorem is referenced by:  dfse2  4977