Subtracts two objects from another
-=
op_SelfAddition(other)
table = {
a = 10,
op_SelfAddition = function(other)
{
table.a = table.a - other.a
return table
}
}
o = {
a = 9,
op_SelfAddition = function(other)
{
o.a = o.a - other.a
return o
}
}
table -= other //table.a == 1