Special case of four variable logic function (k-maps)

[Orikon]

I need help with this problem, so far I've only been using trial and error but I'm getting nowhere, and can't think of any other way to figure this out.

Anyway, the problem is to find a four-variable logic function whose minimal sum-of-products realization is not hazard free, but for which there exists a hazard-free sum-of-products realization with fewer product terms than the complete sum.

Any help would be appreciate :)

 

[berkeman]

I asked in your other thread, but I'll ask again here too in case the threads get separated. What do you mean by the term "hazard" in the context of logic design?