<set type> "{" <expr1> "," ... "," <exprn> "}"
A set constructor is an set-valued expression. <set type> may be any set type (see section Set Types). The expressions <expr1> .. <exprn> must be expressions that evaluate to elements of the set's base type. An <expr> may also be of the form <lo>..<hi>, as a shortcut for including several values. For example:
CONST
Letters = SET OF CHAR{'A'..'Z', 'a'..'z'};
VAR
punctuation: SET OF CHAR := SET OF CHAR{'.', '!', ',', ';', '?'};