Theorem baseval 13125

Description: Value of the base set extractor. (Normally it is preferred to work with ( Base ` ndx ) rather than the hard-coded 1 in order to make structure theorems portable. This is an example of how to obtain it when needed.) (New usage is discouraged.) (Contributed by NM, 4-Sep-2011.)

Hypothesis

Ref	Expression
baseval.k	|- K e. _V

Assertion

Ref	Expression
baseval	|- ( Base ` K ) = ( K ` 1 )

Proof of Theorem baseval

Step	Hyp	Ref	Expression
1		baseval.k	. 2 |- K e. _V
2		df-base 13078	. 2 |- Base = Slot 1
3		1nn 9144	. 2 |- 1 e. NN
4	1, 2, 3	strnfvn 13093	1 |- ( Base ` K ) = ( K ` 1 )

Syntax hints:   = wceq 1395   e. wcel 2200   _Vcvv 2800   ` cfv 5324   1c1 8023   Basecbs 13072

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-13 2202  ax-14 2203  ax-ext 2211  ax-sep 4205  ax-pow 4262  ax-pr 4297  ax-un 4528  ax-1re 8116

This theorem depends on definitions:  df-bi 117  df-3an 1004  df-tru 1398  df-nf 1507  df-sb 1809  df-eu 2080  df-mo 2081  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ral 2513  df-rex 2514  df-v 2802  df-sbc 3030  df-un 3202  df-in 3204  df-ss 3211  df-pw 3652  df-sn 3673  df-pr 3674  df-op 3676  df-uni 3892  df-int 3927  df-br 4087  df-opab 4149  df-mpt 4150  df-id 4388  df-xp 4729  df-rel 4730  df-cnv 4731  df-co 4732  df-dm 4733  df-rn 4734  df-iota 5284  df-fun 5326  df-fv 5332  df-inn 9134  df-slot 13076  df-base 13078

This theorem is referenced by: (None)