(" < ( <" "implies that is capital letter (" < ( <" "implies that is lower-case letter (" < ( <" "implies that is decimal digit the type char contains non-printingblank character and line-end character that may be used as separators this is text fig representations of text the availability of two standard type transfer functions between the types char and integer is particularly important in the quest to write programs in machine independent form we will call them ord(ch)denoting the ordinal number of ch in the character setand chr( )denoting the character with ordinal number thuschr is the inverse function of ordand vice versathat isord(chr( ) (if chr(iis definedchr(ord( ) furthermorewe postulate standard function cap(chits value is defined as the capital letter corresponding to chprovided ch is letter ch is lower-case letter implies that cap(chcorresponding capital letter ch is capital letter implies that cap(chch the type set the type set denotes sets whose elements are integers in the range to small numbertypically or givenfor examplevariables var rstset possible assignments are :{ } :{xy } :{herethe value assigned to is the singleton set consisting of the single element to is assigned the empty setand to the elements xyy+ - the following elementary operators are defined on variables of type setin set intersection set union set difference symmetric set difference set membership constructing the intersection or the union of two sets is often called set multiplication or set additionrespectivelythe priorities of the set operators are defined accordinglywith the intersection operator having priority over the union and difference operatorswhich in turn have priority over the membership