Week 3 - Context Free Grammars

Question 1

What does each rule in a BNF tell you?

Answer 1

What symbols you can replace a non-terminal symbol with.

Question 2

What 4 things make up a BNF

Answer 2

a finite set of non-terminal symbols
A finite set of terminal symbols
A finite set of rules
The start variable (which is an element of the non-terminal set)

Question 3

what does it mean that BNFs are “context free”?

Answer 3

You can apply a rule to any relevant non-terminal symbol regardless of the other symbols in the string.