[Proof Complexity] Prague seminar on Monday - Raheleh Jalali

thapen thapen at math.cas.cz
Sun Apr 25 00:29:49 CEST 2021

Raheleh Jalali will give a proof complexity talk in our online logic 
seminar on Monday, at 15:30 Prague time - see the announcement below.

To join go to
Passcode: 017107 (if required)


  Speaker:Raheleh Jalali, Utrecht University
  Title: Feasible disjunction property for intuitionistic modal logics


  In this talk, we present a uniform method to prove feasible disjunction 
property (DP) for various intuitionistic modal logics. More 
specifically, we prove that if the rules in a sequent calculus for a 
modal intuitionistic logic have a special form, then the sequent 
calculus enjoys feasible DP. Our method is essentially an adaptation of 
the method used by Hrubes in his lower bound proof for the 
intuitionistic Frege system. As a consequence, we uniformly prove that 
the sequent calculi for intuitionistic logic, the intuitionistic version 
of several modal logics such as K, T, K4, S4, S5, their Fisher-Servi 
versions, propositional lax logic, and many others have feasible DP. Our 
method also provides a way to prove negative results: we show that any 
intermediate modal logic without DP does not have a calculus of the 
given form. This talk is based on a joint work with Amir Tabatabi.

  For more information see the seminar web page at
  https://calendar.math.cas.cz/logic-seminar-actual .

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