Write the syntax of BNF in EBNF (and the other way round).
Produce the grammar for a simple language specifying conventional arithmetic
expressions involving integer constants, brackets and the four binary operators
+, -, * and /. Make sure that expressions of the form 1+2*3 are interpreted
correctly by the grammar. Then extend the grammar to allow the unary operators
+ and -. Make sure that the grammar correctly interprets expressions of the form
-1-2. Maybe produce an implementation, although this will be much easier
once material in later chapters has been read!