is that the NPDA in state q with the input symbol a and Z the symbol on top of the stack, can for any i enter state [p.
is that the NPDA in state q, independently of the input symbol being scanned, and with the symbol R on top of the stack, can enter state [p.
p, aW, X[alpha]) and (q, W, [gamma]a) are known as consecutive instantaneous descriptions and are often used to define the current configuration of the NPDA [2, 3].
0], F) is an NPDA, then the language accepted by M, L (M), is defined by L (M) = {w [member of] [[summation].
Throughout the paper we prove that languages are context free by designing NPDA that accepts them.