Bf grammar Here is a simple context-free grammar for Bf. This grammar has 8 terminals []><+-,. and 3 non-terminals S, L, C. S-> CS | LS | A L-> [S] C->> | < | + |-|, | . You can think of S as the language of all syntactically correct Bf programs. It is simply a sequence of C's and L's, where each C