Disclaimer: This next puzzle wasn't put up in the Oracle Forums, because it doesn't really show off OPA. Indeed, the puzzle takes away strong OPA capabilities and then tries to see if people can still use OPA to solve the problem. On the bright side, this is still a puzzle for members of the OPA community that like to solve puzzles in their free time. (Yes, some of us enjoy keeping up our skills that way.)
The broken keyboard puzzle. I started to invent a story, but the story was too juvenile. So instead, here is the puzzle:
attr d = (attr a + attr b + 5) * attr c
That is a very simple rule, as long as you write it with numbers and symbols such as 5, =, (, +, *, etc…
To solve this puzzle, write the equivalent of that very simple rule in OPA without using any number or symbol characters such as 0-9,=,+,*,(,),[,],-,”,’, etc… You can’t use “5”, can’t use “=”, can’t use “(“ or “)”, can’t use “+” or “*”… and so on…
Inputs attr a, attr b, and attr c are guaranteed to all be integers greater than or equal to 1 and less than or equal to 100.
Trust me, that last guarantee simplifies the puzzle and adds a few more solution options… However, this still isn’t an obvious puzzle to solve.
A solution project is attached - it has some OPA tricks in it.