David Hume is renowned for two pieces of cutlery, the guillotine and the fork.
Hume's guillotine is the sharp cut he makes between "is" statements and "ought" statements, to make the point that the former never ground the latter.
His "fork" is the division between what later came to be called "analytic" and "synthetic" statements, with the ominous observation that any books containing statements that cannot be assigned to one or the other prong should be burnt.
Actually, I should acknowledge that there is some dispute as to how well or poorly the dichotomy Hume outlines really maps onto the analytic/synthetic dichotomy. Some writers maintain that Hume meant something quite different and has been hijacked. Personally, I've never seen the alleged difference however hard they've worked to point it out to me.
The guillotine makes for a more dramatic graphic than a mere fork, hence the bit of clip art above.
I'm curious whether the proposition, "one can deduce nothing about what ought to be from what is" implies "one ought not to try." The former is an "is," after all, and so can imply no "ought" if it is accurate.
More seriously, my own position has long been that goodness is a fact in the world, and rightness is an inference from it. I take that to be the standard premise of teleological ethics. So I don't believe the guillotine does the work Hume wanted it to do.
But the FORK is the subject of this forthcoming article by Matias Slavov, http://users.jyu.fi/~makislav/Articles/Humes_Fork_and_Mixed_Mathematics.pdf
The real purpose of this post is simply to recommend that article as a valuable review of the issue of how distinct these two sorts of proposition can really be, especially in the fact of "mixed" (applied) mathematics. Isn't Sheldon Cooper in the business of figuring out matters of fact by being rigorous as to the relations of ideas?
Well, yes, sort of. But as Slavov explains, Hume's dichotomy is tenable against objections based on such work.
Who is Slavov? This fellow: http://users.jyu.fi/~makislav/