diff --git a/doc/tutorial/gf-tutorial2.txt b/doc/tutorial/gf-tutorial2.txt index 978d46f36..31622a62b 100644 --- a/doc/tutorial/gf-tutorial2.txt +++ b/doc/tutorial/gf-tutorial2.txt @@ -1876,15 +1876,19 @@ In a logical framework, the formalization of a mathematical theory is a set of type and function declarations. The following is an example of such a theory, represented as an ``abstract`` module in GF. ``` - abstract Geometry = { - cat - Line ; Point ; Circle ; -- basic types of figures - Prop ; -- proposition - fun - Parallel : Line -> Line -> Prop ; -- x is parallel to y - Centre : Circle -> Point ; -- the centre of c +abstract Arithm = { + cat + Prop ; -- proposition + Nat ; -- natural number + fun + Zero : Nat ; -- 0 + Succ : Nat -> Nat ; -- successor of x + Even : Nat -> Prop ; -- x is even + And : Prop -> Prop -> Prop ; -- A and B } ``` +A concrete syntax is given below, as an example of using the resource grammar +library.