Maude-help mailing list

["Scott" <scottxyz AT usa.net>]

Hello --

I think I've answered my own question posted here:

http://maude.cs.uiuc.edu/pipermail/maude-help/2006-February/000161.html

and mentioned again here:

http://maude.cs.uiuc.edu/pipermail/maude-help/2006-April/thread.html

In my original post, I asked why the following code would not compile:

(view Tuple3{X :: TRIV , Y :: TRIV , Z :: TRIV} from TRIV to TUPLE[3]{X,Y,Z}
is
  sort Elt to Tuple{X,Y,Z} .
endv)

(fmod SET-TUPLE3{X :: TRIV , Y :: TRIV , Z :: TRIV}
  is
  pr SET{Tuple3{X,Y,Z}} .
endfm)

(fmod SET-TUPLE3-NNN is
  pr SET-TUPLE3{Nat,Nat,Nat} .
endfm)

Now I see it should have been written more simply:

(view Tuple3{X :: TRIV , Y :: TRIV , Z :: TRIV} from TRIV to TUPLE[3]{X,Y,Z}
is
  sort Elt to Tuple{X,Y,Z} .
endv)

(fmod SET-TUPLE3-NNN is
  pr SET{Tuple3{Nat,Nat,Nat}} .
endfm)

I parameterized in too many places in my original post, leading to a module
which would not compile. The module SET-TUPLE3{X :: TRIV , Y :: TRIV , Z ::
TRIV} was not necessary.

Given the module SET already parameterized over {X0} and the module
constructor TUPLE[3] already parameterized over {X1,X2,X3}, it was redundant
to introduce a module SET-TUPLE3 parameterized over {X4,X5,X6}. The
parameterized view from TRIV to TUPLE[3]{X1,X2,X3} was sufficient to allow
creating a module SET{Tuple3{X1,X2,X3}}.

-- Scott Alexander