Consult the language reference manuals to determine (i)the sets if characters that form the input alphabet(excluding those that may only appear in character strings or comments) (ii)the lexical form of numerical constants (iii)the lexical form of identifiers, for languages: (a)C (b)C++ (c)C# (d)Fortran (e)Java (f)Lisp (g)SQL C (according to ISO C Standard draft n1256 , Sep 2007) same as C++ , based on wiki (https://en.wikipedia.org/wiki/C_(programming_language)#Character_set) same as C++ same as C++ C++ (according to ISO C++ Standard draft n3787 , Oct 2013) [A-Za-z0-9] | [_[]#()<>%:;.?*+-/^&|~!=,\"'] | space, tab, vertical tab, feed, new-line , Based on section 2.3, C++ Standard. For instance : integer-literal: decimal-literal integer-suffixopt check C++ Standard section 2.14 for the rest, which are too tedious to paste here. Copied from section 2.11, C++ standard: identifier: identifier-nondigit identifier identifier-nondigit identifier digit identifier-nondigit: nondigit universal-character-name other implementation-defined characters nondigit: one of a b c d e f g h i j k l m n o p q r s t u v w x y z A B C D E F G H I J K L M N O P Q R S T U V W X Y Z _ digit: one of 0 1 2 3 4 5 6 7 8 9 C# (according to C# Language Specification Version 5.0, 2012 ) A Unicode character escape sequence check section 2.4.1 for more. check section 2.4.4 for numerical constands. check section 2.4.2 for identifiers. Fortran95 (according to ISO Fortran Standard draft...