index.md (1184B)
1 +++ 2 title = 'Standard translation: mapping basic modal logic to first-order predicate logic' 3 +++ 4 # Standard translation: mapping basic modal logic to first-order predicate logic 5 Aim to map formulas of basic modal logic to first-order predicate logic such that: 6 - φ in BML is *valid* iff its translation in first-order predicate logic is *valid* 7 - φ in BML is *satisfiable* iff its translation in first-order predicate logic is *satisfiable* 8 9 Translation: 10 - translate "p is true in world x" as "predicate P holds for x" 11 - translate "accessibility relation R" as "binary predicate R" 12 - translation is relative to some state 13 - notation: Px instead of P(x), Rxy instead of R(x,y) 14 15 Rules for standard translation: 16 17 ![Standard translation rules](standard-translation-rules.png) 18 19 Examples of translation: 20 21 ![Standard translation examples](standard-translation-examples.png) 22 23 first-order predicate logic is decidable _if it uses at most 2 variables_. 24 therefore, adapt standard translation to only use 2 variables. 25 26 In a formula, check the situation with bound variables, and rename where possible. 27 When you are in state _a_ and start a quantification, use the variable _b_, and vice versa.