Magnetic Semantics?

[wordplay]

So I'm moved into the new office and I just pulled out my Magnetic Phonetics kit, and I really really want some kind of Magnetic Semantics kit, filled with quantifiers and operators and all manner of brackets. Combined with a basic magnetic poetry kit, the side of my cabinet that faces the door could be a true wonder of language symbolic geekitude. Anybody ever seen anything like this? C'mon, if the IPA has been magnetized, surely first-order logic (which is much more widely used, yes?) has been!