(*a)
return t
product of tensors
product of tensors
product of tensors
def tensor_mul(*a):
    """
    product of tensors
    """
    if not a:
        return TensMul.from_data(S.One, [], [], [])
    t = a[0]
    for tx in a[1:]:
        t = t*tx
    return t
def tensor_mul ( * a ) : if not a : return TensMul . from_data ( S . One , [ ] , [ ] , [ ] ) t = a [ 0 ] for tx in a [ 1 : ] : t = t * tx return t