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Definition df-lsw 12547
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 12539 . 2  class lastS
2 vw . . 3  setvar  w
3 cvv 3109 . . 3  class  _V
42cv 1394 . . . . . 6  class  w
5 chash 12408 . . . . . 6  class  #
64, 5cfv 5594 . . . . 5  class  ( # `  w )
7 c1 9510 . . . . 5  class  1
8 cmin 9824 . . . . 5  class  -
96, 7, 8co 6296 . . . 4  class  ( (
# `  w )  -  1 )
109, 4cfv 5594 . . 3  class  ( w `
 ( ( # `  w )  -  1 ) )
112, 3, 10cmpt 4515 . 2  class  ( w  e.  _V  |->  ( w `
 ( ( # `  w )  -  1 ) ) )
121, 11wceq 1395 1  wff lastS  =  ( w  e.  _V  |->  ( w `  ( (
# `  w )  -  1 ) ) )
Colors of variables: wff setvar class
This definition is referenced by:  lsw  12593  sseqval  28524  sseqfv1  28525  sseqfn  28526  sseqf  28528  sseqfv2  28530
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