A computer, a Commodore 64 at least, is not a perfect substitute for the board game.
The two groups are not "perfect substitutes," even when they have similar education and the same occupation.
If the groups were perfect substitutes, the change would be the same.
Every product is perfectly homogeneous and a perfect substitute for any other.
Peaceful negotiations are always a perfect substitute to mayhem and violence.
If financial assets were perfect substitutes for one another, the yields on each would be identical.
In the portfolio balance approach, domestic and foreign bonds are not perfect substitutes.
They may both be great movies, but they're not perfect substitutes.
One good is a perfect substitute for another only if it can be used in exactly the same way.
That is, they are hardly perfect substitutes for one another.