Ok. I assume that the number line stuff was to help clear up some confusions I had and then lead me into finding a solution to or(x,y). Or not, maybe you were just teaching me some stuff about how number lines work. Regardless I didn’t use the preceding information with number lines to come up with my solution.
If I’m understanding the difference between integer and real arithmetic correctly so far my solution of x+y-xy should work.
I got my solution by assuming that some of the stuff I did with logic would work directly with math. So or(x,y) = not(and(not(x),not(y)). In in-fix: !(!x&!y). Translating that to math: 1-((1-x)*(1-y)). That simplifies down to x+y -xy. Here’s the math to show that works:
x y
1 1 = 1 + 1 - (1)(1) = 2 - 1 = 1
1 0 = 1 + 0 - (1)(0) = 1 - 0 = 1
0 1 = 0 + 1 - (0)(1) = 1 - 0 = 1
0 0 = 0 + 0 - (0)(0) = 0 - 0 = 0