I would like a set of combinators, that can take to wire Signals and calculate for each Signal type (eg iron) a*b, a/b, min(a,b) or max(a,b).

More details please

so, you have a combinator with 2 Inputs and one Output and Name the Inputs iron_a, iron_b or solid_fuel_a, solid_fuel_b etc and then you have the Option to say for each Signal type (each letter, number, item...) you define Signal_out:= Signal_a * Signal_b. The "*" in the last equation can of Course be replaced by any other in game Operation (-,min,max,/) (+ is not really useful as it is the Basic way factorio adds Signals)

So you have (for example) two iron inputs of different sources you want to perform math on directly using one combinator?

exactly. but on the same time i want to be able to apply the same Operation to all Signals, eg iron, copper, water and all other Signals.

Will look into it and see if I can come up with something from this :)