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Definition df-lsw 12496
Description: Extract the last symbol of a word. May be not meaningful for other sets which are not words. The name lastS (as abbreviation of "lastSymbol") is a compromise between usually used names for corresponding functions in computer programs (as last() or lastChar()), the terminology used for words in set.mm ("symbol" instead of "character") and brevity ("lastS" is shorter than "lastChar" and "lastSymbol"). Labels of theorems about last symbols of a word will contain the abbreviation "lsw" (Last Symbol of a Word). (Contributed by Alexander van der Vekens, 18-Mar-2018.)
Assertion
Ref Expression
df-lsw  |- lastS  =  ( w  e.  _V  |->  ( w `  ( (
# `  w )  -  1 ) ) )

Detailed syntax breakdown of Definition df-lsw
StepHypRef Expression
1 clsw 12488 . 2  class lastS
2 vw . . 3  setvar  w
3 cvv 3106 . . 3  class  _V
42cv 1373 . . . . . 6  class  w
5 chash 12360 . . . . . 6  class  #
64, 5cfv 5579 . . . . 5  class  ( # `  w )
7 c1 9482 . . . . 5  class  1
8 cmin 9794 . . . . 5  class  -
96, 7, 8co 6275 . . . 4  class  ( (
# `  w )  -  1 )
109, 4cfv 5579 . . 3  class  ( w `
 ( ( # `  w )  -  1 ) )
112, 3, 10cmpt 4498 . 2  class  ( w  e.  _V  |->  ( w `
 ( ( # `  w )  -  1 ) ) )
121, 11wceq 1374 1  wff lastS  =  ( w  e.  _V  |->  ( w `  ( (
# `  w )  -  1 ) ) )
Colors of variables: wff setvar class
This definition is referenced by:  lsw  12537  sseqval  27953  sseqfv1  27954  sseqfn  27955  sseqf  27957  sseqfv2  27959
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