Handle : A “handle” of a string is a substring of a string that matche the right side of a production, and whose reduction to the non terminal of the production is one step along reverse of rightmost derivation Handle pruning : The process of discovering a handle and reducing it to the appropriate Left Hand side non terminal is known as handle pruning. Right sentential form Handle Reducing production id1+id2*id3 id1 E --> id E+id2*id3 id2 E --> id E+E*id3 id3 E --> id E+E*E E*E E --> E*E E + E E + E E --> E + E E Left Factoring Left Factoring is a grammar transformation technique. It consists in "factoring out" prefixes which are common to two or more productions. For example, going from: A ? a ß | a ?
