- In logic, a quantifier is an operator that specifies how many individuals in the domain of discourse satisfy an open formula. For instance, the universal quantifier ∀ in the first order formula ∀xP(x) expresses that everything in the domain satisfies the property denoted by P. On the other hand, the existential quantifier ∃ in the formula ∃xP(x) expresses that there exists something in the domain which satisfies that property. A formula where a quantifier takes widest scope is called a quantified formula. A quantified formula must contain a bound variable and a subformula specifying a property of the referent of that variable.
- My favorite “Schurik” story (deniseelaineheap.substack.com)
Out on summer break, Alexander Schmorell and two friends decided to bike from Munich to Donauwörth, intending to catch a boat and float down the Danube to Austria. On paper, the 100-kilometer (60 mile) bike ride looked easy. The terrain was relatively flat, a biker’s paradise.