def log(a):
'''Natural logarithm of input'''
return _maths.log(a)
def log(a):
"""Natural logarithm of input"""
return _maths.log(a)
def log(a):
'''Natural logarithm of input'''
return _maths.log(a)
def log(a):
"""Natural logarithm of input"""
return _maths.log(a)