Explanation for APR Display

At present, the Supply APR on the Flux interface is shown as "Flux Distribution APR - Borrow APR".

Basically, if the result is positive, it means that the realised value of the rewarded $FLUX is not enough to offset the borrow interest; if the result is negative, it means that the realised value of the rewarded FLUX can offset the borrow interest, and there is extra benefit.