Phrase structure grammar
\(
\begin{array}{lcl}
< program > & ::= & < exp > \\
< exp > & ::= & < var\ exp > | < fn\ exp > | < app\ exp > | < intlit\ exp > \\
& | & < papp1\ exp > | < papp2\ exp > | < if\ exp> | < let\ exp > \\
& | & < print\ exp > | < print2\ exp > | < assign\ exp > \\
< fn\ exp > & ::= & fn\quad '('\ < var\ exp >^*\ ')'\ =>\ < exp > \\
< app\ exp > & ::= & '('\ < exp >\ < exp >^*\ ')' \\
< papp1\ exp > & ::= & < prim1\ op >\ '('\ < exp >\ ')' \\
< papp2\ exp > & ::= & '('\ < exp >\ < prim2\ op >\ < exp >\ ')' \\
< args > & ::= & ( < exp >\ (\ ','\ < exp > )^*\ )?\\
< let\ exp > & ::= & let\ (< var\ exp >\ =\ < exp >)^+\ in\ < exp > (\ ';'\ < exp >)^*\ end\\
< print\ exp > & ::= & print < exp > \\
< print2\ exp > & ::= & print\ " < var exp > " ( ':'\ |\ < exp >) \\
< assign\ exp > & ::= & set\ < var\ exp >\ =\ < exp > \\
< if\ exp > & ::= & if < exp >\ then\ < exp >\ else\ < exp > \\
\end{array}
\)
Lexical grammar
\(
\begin{array}{lcl}
< var\ exp > & ::= & < letter >\ (\ < letter >\ |\ < digit >\ |\ \ \_\ \ )^*\\
< intlit\ exp > & ::= & < digit >^+\\
< digit > & ::= & 0\ |\ 1\ |\ 2\ |\ ...\ |\ 8\ |\ 9\\
< letter > & ::= & a\ |\ b\ |\ ...\ |\ z\ |\ A\ |\ B\ |\ ...\ |\ Z\\
< prim1\ op > & ::= & not\ |\ \sim\ |\ add1\\
< prim2\ op > & ::= & +\ |\ -\ |\ *\ |\ /\ |\ \%\ |\ \lt\ |\ \gt\ |\ === \\
\end{array}
\)