In 1569 Gerardus Mercator solved the projection problem by producing his famous world map with the meridians vertical and parallels having increased spacing in proportion to the secant (a trigonometric function) of the latitude.
What makes the "projection problem" problematic?
This is the so-called "projection problem" for presuppositions.
However, it was not until Karttunen (1973) that the full complexity of the projection problem became apparent.
We then apply these results to von Neumann algebra cohomology theory and the bounded projection problem for von Neumann algebras.
The projection problem is solved twofold in this formalism: by goal regression and by knowledge base progression.
In particular, we examine the belief projection problem: what is believed after performing an action and/or receiving new information?
Temporal projection problem [9]: asks whether a formula holds after a sequence of actions is performed in the initial situation.
The PHD method is shown to be equivalent to a geometrical projection problem which can be solved using ℓ1-norm optimization.
A correct theory of just how presuppositions are inherited from simple to complex sentences would solve the projection problem, and doing so seems to be required for a semantic account of presupposition.
