def string(self, **kwargs):
'''
Format as "fraction(A, B)".
'''
return Operation.string(self, **kwargs)
def string(self, **kwargs):
if self.operands.is_single():
# Single operand: wrap it in square braces to show
# we are treating it as an operator (a function).
return '[' + self.operand.string() + ']'
return Operation.string(self, **kwargs)
