Start with the grammar G6, repeated here:

::= + |

::= * |

::= () | a | b | c

Modify it in the following ways:

a. Add subtraction and division operators (- and /) with the customary precedence and associativity.

b. Add unary negation (-) with right associativity and precendence higher than multiplication and lower than parentheses.

Here's what I have so far, please let me know if this looks good or what I need to change:

::= + | |

::= * | / |

::= (-) | ()

::= () | a | b | c