Derivation TreeDerivation tree is a graphical representation for the derivation of the given production rules for a given CFG. It is the simple way to show how the derivation can be done to obtain some string from a given set of production rules. The derivation tree is also called a parse tree. Parse tree follows the precedence of operators. The deepest subtree traversed first. So, the operator in the parent node has less precedence over the operator in the subtree. A parse tree contains the following properties:
Example 1:Production rules: Input Step 1: Step 2: Step 2: Step 4: Step 5: Note: We can draw a derivation tree step by step or directly in one step.Example 2:Draw a derivation tree for the string "bab" from the CFG given by Solution: Now, the derivation tree for the string "bbabb" is as follows: The above tree is a derivation tree drawn for deriving a string bbabb. By simply reading the leaf nodes, we can obtain the desired string. The same tree can also be denoted by, Example 3:Construct a derivation tree for the string aabbabba for the CFG given by, Solution: To draw a tree, we will first try to obtain derivation for the string aabbabba Now, the derivation tree is as follows: Example 4:Show the derivation tree for string "aabbbb" with the following grammar. Solution: To draw a tree we will first try to obtain derivation for the string aabbbb Now, the derivation tree for the string "aabbbb" is as follows:
Next TopicAmbiguity in Grammar
