If Only

Embedding If and Only If

Compounds of indicative conditionals present some puzzling phenomena. Perhaps most striking, some nested indicative conditionals are uninterpretable. Proponents of NTV hold that indicative conditionals do not have truth values, and they use this to explain why nested indicative conditionals are sometimes uninterpretable: the embedded conditional does not provide the truth conditions needed by t...

If only we all cared.

OnTruth-Conditions for If (but Not Quite Only If )

For—according to the lore—any attempt at pullingoff this featwill reduce themtomaterial implicationand that is decidedlynot agoodwayof assigning truth-conditions to ordinary indicative if s. That is too bad since it seems like they are bounded from above by strict implication (they are true when their antecedents straight out imply their consequents), are bounded from below by material implicat...

Markets are efficient if and only if P = NP

I prove that if markets are efficient, meaning current prices fully reflect all information available in past prices, then P = NP , meaning every computational problem whose solution can be verified in polynomial time can also be solved in polynomial time. I also prove the converse by showing how we can “program” the market to solve NP -complete problems. Since P probably does not equal NP , ma...

What if feedback only counted if the learner used it?

Most teachers give written feedback because it is a required deliverable, like a checkout assistant handing every customer the printed receipt, even though few use them. However there is no point in giving feedback unless the learner uses it: modifies or actively reappraises something specific as a result. This paper explores the theoretical and practical implications of taking this as the star...