Chapter 2.3, Problem 34CYU

Explanation of Solution

Constructing FIRST set and FOLLOW set by obvious facts:

• Obvious facts occurs when one can make use of an adjacent pair or a pair of symbol presented in the right hand side.
• One can deduce a large set of fact into a small set of fact table between a second pass over the grammar.
• The following example shows obvious facts for FIRST set and FOLLOW set.

        $\begin{array}{l}\text{E}\to \text{E+T}\text{\$\$}\text{+}\in \text{FOLLOW(E)}\\ \text{E}\to \text{T TT}\\ \text{TT}\to \text{add\_op}\\ \text{TT}\to \text{EPS(TT)=true}\end{array}$

        $\begin{array}{l}\text{T }\to \text{F FT}\\ \text{FT}\to \text{mul\_op}\\ \text{FT}\to \in \text{EPS(FT)=true}\\ \text{F}\to (\text{E})(\in \text{FIRST(F)}\text{and}\in \text{FOLLOW(E)}\\ \text{F}\to <\end{array}$