A) Show that the following grammar is ambiguous:

:= |

::= wilma | betty |

::= fred | barney |

B)

The following grammar is ambiguous:

:= |

::= wilma | betty |

:= fred | barney |

Fix it

C)

Start with the grammar G7, defined here. G7:

::= {+}

::= {*}

::='('')' | a | b | c

Modify it in the following way:

Add subtraction and division operator (- and /) with the customary precedence and associativity. However, the * and / shall always go first comparing with + and /.