Among simple $$LR (SLR) ,$$ canonical $$LR,$$ and look-ahead $$LR$$ $$(LALR),$$ which of the following pairs identify the method that is very easy to implement and the method that is the most powerful , in that order?

Match the following:

GROUP 1	GROUP 2
P. Lexical analysis	1. Graph coloring
Q. Parsing	2. DFA minimization
R. Register allocation	3. Post-order traversal
S. Expression evaluation	4. Production tree

Which one of the following is TRUE at any valid state in shift-reduce parsing?

Consider the grammar defined by the following production rules, with two operators * and +

$$\eqalign{ & S \to T*P \cr & T \to U\,|\,T*U \cr & P \to Q + P\,|\,Q \cr & Q \to id \cr & U \to id \cr} $$

Which one of the following is TRUE?