Define Alphabet and String?
A finite set of symbols is termed as alphabet. An alphabet is frequently signified by sigma, yet can be specified any name.
B = {0, 1} here B is an alphabet of two symbols, 0 and 1.
C = {a, b, c} here C is an alphabet of three symbols, a, b and c.
Occasionally space and comma are in an alphabet while other times such are Meta symbols utilized for descriptions. Over an alphabet a language is defined. For illustration binary language is defined over alphabet B.
A finite sequence of symbols from an alphabet is termed as string or word.
From the alphabet strings B above strings are 01110 and 111. aaabccc and b both are strings from the alphabet C above.
A null string is a string without symbols, generally denoted through epsilon has zero length.