•A syntax tree or parse tree
is an ordered labeled tree such that:
–a) terminal nodes (leaf nodes) are
labeled by terminal symbols
–b) non-terminal nodes (internal
nodes) are labeled by non-terminal symbols.
–c) each non-terminal node labeled
by N has children X1, X2, ... Xn (in this order) such that N := X1 X2 ... Xn is a production.