Definition df-lsw 11372

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 11371	. 2 class lastS
2		vw	. . 3 setvar 𝑤
3		cvv 2821	. . 3 class V
4	2	cv 1401	. . . . . 6 class 𝑤
5		chash 11236	. . . . . 6 class ♯
6	4, 5	cfv 5380	. . . . 5 class (♯‘𝑤)
7		c1 8186	. . . . 5 class 1
8		cmin 8504	. . . . 5 class −
9	6, 7, 8	co 6088	. . . 4 class ((♯‘𝑤) − 1)
10	9, 4	cfv 5380	. . 3 class (𝑤‘((♯‘𝑤) − 1))
11	2, 3, 10	cmpt 4193	. 2 class (𝑤 ∈ V ↦ (𝑤‘((♯‘𝑤) − 1)))
12	1, 11	wceq 1402	1 wff lastS = (𝑤 ∈ V ↦ (𝑤‘((♯‘𝑤) − 1)))

This definition is used by:  lswwrd  11373