nonthesis

Not being or relating to a thesis.

Something that is posited in order to be disproved.

...or theses, and non-derivable propositions, non-theses, while also assigning an operator to relate the two, since the negation of a non-thesis should give us a derivable thesis.

we can do both: prove theses and extract falsifying models for non-theses on the basis of unsuccessful derivations.