 In 1965 Donald Knuth invented the LR(k) parser (Left to right, Rightmost derivation parser) a type of shift-reduce parser, as a generalization of existing precedence parsers.This parser has the potential of recognizing all deterministic context-free languages and can produce both left and right derivations of statements encountered in the input file.Knuth proved that it reaches its maximum language recognition power for k=1 and provided a method for transforming LR(k), k > 1 grammars into LR(1) grammars.