If-Thenism

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...

Even if after If then conditionals

This study evaluates how people represent “even if” conditionals when they have to integrate them with previous “if then” conditionals and also make an inference. The terms in the premises were ordered to facilitate their integration (Figure 1: If A then B; Even if B C). In half the cases, the “even if” conditional was expressed with a negation instead of an affirmation (If A then B; Even if no...

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...

"If not us, who? If not now, when?".