Context free grammar and push down automata.

Question

Is true..?

 

In an unambiguous grammar every string has exactly one derivation.

Comments

exactly one Leftmost derivation or exactly one Rightmost derivation

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Thank you:)

Answer 1

true

  ambiguous grammar is a  grammar for which there exists a string that can have more than one leftmost derivation or right most derivation or parse tree,

 unambiguous grammar is a  grammar for which every  string has a unique leftmost derivation or right most derivation or parse tree.