Convert the following EBNF grammar to a BNF grammar:Consider the following EBNF grammar:

plainid $->$ alphaid I op

alphaid $->$ upper idrest I varid

varid $->$ lower idrest

idrest $\{$letter I digit$\}[\text{'}-\text{'}$ op$]$

lower $\text{'}a\text{'}|...$ I $\text{'}$z$\text{'}|\text{'}\_\text{'}$

upper $\text{'}$A$\text{'}|...$ I $\text{'}$Z$\text{'}|\text{'}$$$\text{'}$

op $$ opchar $\{$opchar $\}$

letter $->$ upper I lower

digit $\text{'}\text{'}0\text{'}|...$ I $\text{'}9\text{'}$

opchar $->\text{'}!\text{'}|\text{'}$#$\text{'}|\text{'}\%\text{'}|\text{'}$&$\text{'}|\text{'}*\text{'}|\text{'}+\text{'}|\text{'}-\text{'}|\text{'}/\text{'}|\text{'}$:$\text{'}|$

@$\text{'}|\text{'}\text{'}|\text{'}^\text{'}|\text{'}|\text{'}|\text{'}\text{'}$

Write a BNF grammar to represent the EBNF grammar above. You only need to include

the rules that need to be rewritten $($those with optional parts or repetition$)$ and any

additional rules necessary to convert the EBNF grammar to BNF$.$ In other words, don't

restate the rules that will remain the same.