Definition df-lsw 11208

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 ∈ V ↦ (𝑤‘((♯‘𝑤) − 1)))

Detailed syntax breakdown of Definition df-lsw

Step	Hyp	Ref	Expression
1		clsw 11207	. 2 class lastS
2		vw	. . 3 setvar 𝑤
3		cvv 2803	. . 3 class V
4	2	cv 1397	. . . . . 6 class 𝑤
5		chash 11083	. . . . . 6 class ♯
6	4, 5	cfv 5333	. . . . 5 class (♯‘𝑤)
7		c1 8076	. . . . 5 class 1
8		cmin 8392	. . . . 5 class −
9	6, 7, 8	co 6028	. . . 4 class ((♯‘𝑤) − 1)
10	9, 4	cfv 5333	. . 3 class (𝑤‘((♯‘𝑤) − 1))
11	2, 3, 10	cmpt 4155	. 2 class (𝑤 ∈ V ↦ (𝑤‘((♯‘𝑤) − 1)))
12	1, 11	wceq 1398	1 wff lastS = (𝑤 ∈ V ↦ (𝑤‘((♯‘𝑤) − 1)))

This definition is referenced by:  lswwrd  11209