Among simple LR (SLR) , canonical LR, and look-ahead LR (LALR), which of the…

Answer: SLR, canonical LR

• Why SLR is very easy to implement: builds an LR(0) automaton and uses follow sets to decide reductions, so the algorithm and tables are simpler and smaller to construct.

• Why canonical LR is the most powerful: uses full LR(1) items with one-symbol lookahead attached to each item so it distinguishes more contexts, avoiding conflicts that SLR and sometimes LALR cannot; it can recognize all deterministic LR(1) grammars.

Note: LALR is a practical compromise (it merges canonical LR states to reduce table size) and is often sufficient in practice, but it is not strictly as powerful as canonical LR.