; It is known that the language The language L = {a^nb^nc^n | n >= 1}is not context free. ; However, with the use of the look ahead operators we can construct a grammar ; that accepts those phrases and only those phrases. S = &(AB !b) *a BC !c AB = a [AB] b BC = b [BC] c a = %s"a" b = %s"b" c = %s"c"