ket arithmetic

OK, a slightly weird one today. We can actually do some simple arithmetic just using the coeffs of kets. Though they are fixed numbers, rather than parameters, so you can't do all that much interesting with them.

Anyway, some examples:

-- 3.2 + 5.3 + 7
sa: 3.2|x> + 5.3|x> + 7|x>
15.5|x>

-- 3.2 + 5.3 - 7
sa: 3.2|x> + 5.3|x> + -7 |x>
1.5|x>

-- 5 * 11 * 17
sa: 5 11 17 |x>
935|x>

-- 9/5 * 10
sa: 9/5 10 |x>
18|x>

-- 13^9
sa: 13^9 |x>
10604499373|x>

-- 5.2^2 (3 + 7.1 + 9.8)
sa: 5.2^2 (3|x> + 7.1|x> + 9.8|x>)
538.096|x>

-- 2 * 3 * 7^7 (5 + 9.2)
sa: 2 3 7^7 (5|x> + 9.2|x>)
70165863.6|x>

And I guess that is it. It should be obvious from there how to do arbitrary arithmetic using ket coeffs.