Timeline for Why are variables logical symbols, but predicates non-logical symbols in predicate logic?
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| Apr 23, 2021 at 15:59 | vote | accept | csp | ||
| Apr 23, 2021 at 12:46 | comment | added | Mauro ALLEGRANZA | Maybe we can say that we have logical symbols (connectives, quantifiers), non-logical symbols and variables (and sometimes auxiliary symbols, like parentheses). When we put variables with the "logical sides", this is due to the fact that with a specific formalized theory we have a specific (and limited) set of non-logical symbols: "in" for set theory, plus and minus and zero for arithmetic, and so on, while the individual variables are always all there and the same. | |
| Apr 23, 2021 at 5:41 | comment | added | Conifold | Because predicates stand for something that is interpreted (as relations) on the domain of discourse, while variables are just placeholders that indicate positions where each quantifier applies. It is constants that are interpreted as objects in the domain, not variables. | |
| Apr 23, 2021 at 2:48 | answer | added | Double Knot | timeline score: 2 | |
| Apr 23, 2021 at 2:26 | history | asked | csp | CC BY-SA 4.0 |