Construction of contextual grammars
The concept of a contextual grammar is slightly generalized here; the generalized grammars called contextual hypergrammars admit to introduce the so called reducing operators. Using some results concerning these operators a construction is described assigning a contextual grammar G(n)(V, L) to any language (V, L) and to any nonnegative integer n. This construction has the following property: The language (V L) is generated by a contextual grammar if and only if there exists a nonnegative integer n(0) such that G(n) (V, L) = G(n0) (V, L) for any n >= n(0).
contextual grammar contextual hypergrammar reducing operator