I was wondering if there was any way to reassign the "||" operator to calculate parallel resistors?

like this:

R1 || R2 = (1/R1+1/R2)^(-1)

I have a piecevise defined function where i wanna reference the condition inorder to use the maximum and minimum values of the defined range in other functions. Is there a function for this that i just cant find or do i have to use a workaround?

These are the values im trying to access. and heres the function:

f := proc (t) options operator, arrow; piecewise(-1 < t and t <= 0, t+1, 0 < t and t <= 1, 1-t) end proc