incorporate JM Vanels comments

[Anniepoo]

http://www.pathwayslms.com/swipltuts/dcg/index.html#anchintro
some_terminals --> [this, is, a, teminal],
We shall use the nonterminal as//0
Notation : A DCG head with functor f and arity N is referred to as f//N to distinguish it from a regular Prolog predicate, which we refer to as f/N. : should be said early !!!!!!!!!!
1_4 Variables in Body : more details welcome !!!!!!!!