Consider the syntax directed translation given by the following grammar and semantic rules. Here N,I,F and B are non-terminals. N is the starting non-terminal, and #,0 and 1 are lexical tokens corresponding to input letters \text{“#", “0" and “1"}, respectively. X.val denotes the synthesized attribute (a numeric value) associated with a non-terminal X.I1 and F1 denote occurrences of I and F on the right hand side of a production, respectively. For the tokens 0 and 1,0.val=0 and 1.val=1.