Add a single `@rule` to `simplify`

[greimel]

I would it be nice if one could easily add a custom simplification rules on top of the default rules in simplify.

@shashi said on slack, that this is not so easy currently, and asked me to open an issue here.

[mmikhasenko]

It seems to be solved with

expr = 1/Symbolics.Term(sqrt, 2))^2 
#
r1 = @rule sqrt(~x)^2 => ~x
r2 = @rule (~x/~y)^2 => (~x)^2 / (~y)^2
#
simplify(expr, RuleSet([r1,r2]))

[greimel]

Not sure. Doesn't that only use the two specified rules?

I'd like all predefined rules plus one or two extra.

[mmikhasenko]

I see. You are probably right. One might need to apply one more |> simplify after your extra rule.