Consider the following further simplified version of Prolog we have discussed in class: Axioms as given in Horn clause form. Variables in head are universally quantified. Variables in body only are existentially quantified. A query is a clause without a head. A fact is a clause without a body. A prolog program is composed of a list of clauses and one or more queries. There are no functions. Note that lack of functions will render this language very weak since useful arithmetic and many other things cannot be done without functions. A BNF for this simplified version Prolog is given below: - | := I != | : = I , ::= | ( | , = | | = " - = a b c ... 1x 1 V12 ... all characters := | - | := I != | : = I , ::= | ( | , = | | = " - = a b c ... 1x 1 V12 ... all characters := |