Well, in electronic when you want to know the resistent in any circuit, you need to sum the all resistent.

in series resistors are added

but in parallel the resistors are added like as admitances, for example.

In this example Rab= R1//R2//...//Rn

The "//" be read as "with parallel of"

The program.

The program interpret the parallels separated by ",", and too calc the expresions between ",", and interpret the "(..)".

When you input

7,5 (this is real 7//5 or ((1/7 + 1/5)^(-1)) = 2.9166

but you can input a expresion, for example 3+4 = 7 the prev example be write too like as:

3+4,5 = 2.9116 (in real 3+4 are 2 resistent in series R1 + R2 = 7, this expresion is equal to (R1+R2)//R3 )

Repeat this is a "

**Parallel interpret separeted by ',' **" for this reason in this example

**not do first** 4//5 then plus 3

And interpret "(...)" real is a loop when find "( ... )" solve this, replaces in the expresion and search for other "(...)", then solve the expresion.

((4,5)+3) , In this case first solve the 4//5, then plus 3

Summary: "," is the parallel of any.

Bye!

**Edited by sebest, 03 July 2012 - 01:07 PM.**