Ruby case statement is similar to the switch statement in Java. It has the following syntax:

case expression when expression$1$ then code $...$

when expression$2$ then code $...$

whe n expression$3$ then code $......$ else code end Describe the syntax in BNF$.$ I started it with case$\_$stmt $->$ case expr when when$\_$clause then stmt and then I$\text{'}$m not sure where to go from here, if this even how to start it$.*$I$\text{'}$m not adding the angled brackets because it doens't show the words inside of it for some reason $*$ Also I undestand how to do the parse tree and derivation when I have the BNF rules already, I was just never really taught how to actually describe the syntax in BNF so any help would be amazing. $-$Also here's the code I'll be using to ch eck $/$ make the tree and derivation from the rule:

grade $=\text{'}$C$\text{'}$

case grade

when $\text{'}$A$\text{'}$

then puts "Amazing!!"

when $\text{'}$B$\text{'}$

then puts "Good Job!"

when $\text{'}$C$\text{'}$

then puts $"$C$\text{'}$s get degrees!"

else

puts "Put a little more effort in and ask for help!"

end