 A grammar that is conflict-free for a canonical LR generator but has conflicts in an LALR generator is called LR(1) but not LALR(1), and not SLR.SLR, LALR, and canonical LR parsers make exactly the same shift and reduce decisions when the input stream is correct language.When the input has a syntax error, the LALR parser may do some additional (harmless) reductions before detecting the error than would the canonical LR parser.