mod
*
neg
*Multiply
The * function returns the product of two objects, as follows:
a b->c
#a #b->#c
a [b]->[c]
(a) [b]->[c]
[a] b->[c]
[a] (b)->[c]
[[a]] [b]->[c]
a [[b]]->[[c]]
(a) [[b]]->[[c]]
[[a]] b->[[c]]
[[a]] (b)->[[c]]
[[a]] [[b]]->[[c]]
a_u1 b_u2->c_u3
a_u b->c_u
a b_u->c_u
(a) (b)->(c)