search

rzach / forallx-yyc

UCalgary version of forallx, an introduction to formal logic
https://forallx.openlogicproject.org/
Creative Commons Attribution 4.0 International
94 stars 30 forks source link

Discuss: Is the rule #7 needed in the definition of TFL sentence? #73

Closed kedarmhaswade closed 1 year ago

kedarmhaswade commented 1 year ago

In §6.2, we formally define TFL sentence.

In the given inductive definition that constructs a TFL sentence, is "Nothing else is a sentence." needed? I doubt if it provides any constructive value. It is okay to use it for emphasis, but then it can be a part of exposition, not the definition.

rzach commented 1 year ago

It is a standard part of inductive definitions singling out the set of TFL sentences as the smallest set satisfying the other clauses.