Enter productions of the grammar:

Please note that each character is treated as a symbol and every uppercase alphabet letter is treated as a non-terminal/variable. The tool assumes that the first production given is the starting production of the grammar.
Hyphen (-) and greater-than (>) together signify a rewrite-arrow (→). Use a vertical-bar (|) for seperating alternatives of a production. Use epsilon (ε) to denote a null/empty string.

E.g.