human
I am working on the file "ANTLR4-Python/Earley-Parser/Earley-Parser.ipynb".
The first task is:
The class Grammar represents a context free grammar.  It stores a list of the rules of the grammar.
Each grammar rule of the form
$$ a \rightarrow \beta $$
is stored as the tuple $(a,) + \beta$.  The start symbol is assumed to be the variable on the left hand side of
the first rule. To distinguish syntactical variables form tokens, variables contain only lower case letters,
while tokens either contain only upper case letters or they start and end with a single quote character "'".
Can you write Python code for it?

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Can you provide a the Python code you requested?
assistant
#Here is the Python code you requested.

class Grammar():
    def __init__(self, Rules):
        self.mRules = Rules