Aldor-Meet

On Date: Nov 19, 2007 10:58 AM Oleg Golubitsky wrote to aldor-l :

By analogy with Join, Meet(C1,C2) should return a category which has the intersection of exports of C1 and C2.

A simple test (see below) confirmed this semantics; I also could not find a description of Meet in the guide.

(1) -> <aldor>
#include "aldor"
define C1:Category == with {
       f: Integer;
       g: Integer;
}
define C2:Category == with {
       f: Integer;
       h: Integer;
}
D: Meet(C1,C2) == add {
       f: Integer == 1;  -- OK; if this line is commented out, error:
                               -- The domain is missing some exports.
                               -- Missing f: AldorInteger
}</aldor>

Compiling FriCAS source code from file 
      /var/lib/zope2.10/instance/axiom-wiki/var/LatexWiki/2046275806961882305-25px001.as
      using Aldor compiler and options 
-O -Fasy -Fao -Flsp -lfricas -Mno-ALDOR_W_WillObsolete -DFriCAS -Y $FRICAS/algebra -I $FRICAS/algebra
      . Use the system command )set compiler args to change these 
      options.
#1 (Warning) Could not use archive file `libfricas.al'.

Compiling Lisp source code from file 2046275806961882305-25px001.lsp
   Issuing )library command for 2046275806961882305-25px001

Reading /var/aw/var/LatexWiki/2046275806961882305-25px001.asy
   C1 is now explicitly exposed in frame initial 

   >> System error:
   The function BOOT::ASHARPMKAUTOLOADFUNCTOR is undefined.

The FriCAS library apparently does not define Meet.

#include "fricas"
Meet(T: Tuple Category): Category == with;

define C1:Category == with {
       f: Integer;
       g: Integer;
}
D1: C1 == add {
  f: Integer == 1;
  g: Integer == 2;
}
define C2:Category == with {
       f: Integer;
       h: Integer;
}
D2: C2 == add {
  f: Integer == 1;
  h: Integer == 3;
}

define M12:Category == Meet(C1,C2);

DM12: M12 == add {
  f: Integer == 1;  -- if this line is commented out, error:
                    -- The domain is missing some exports.
  g: Integer == 2;
  h: Integer == 3;

}

define J12:Category == Join(C1,C2);

DJ12: J12 == add {
  f: Integer == 1;
  g: Integer == 2;
  h: Integer == 3;
}

main1():Record(D1hasM12:Boolean,D2hasM12:Boolean) ==
  [D1 has M12, D2 has M12];
main2():Record(M12hasC1:Boolean,DM12hasC2:Boolean) ==
  [DM12 has C1, DM12 has C2];
main3():Record(DJ12hasC1:Boolean, DJ12hasC2:Boolean) ==
  [DJ12 has C1, DJ12 has C2];

main4():Record(D1hasMeet:Boolean, D2hasMeet:Boolean, D1hasF:Boolean) ==
  [D1 has Meet(C1,C2), D2 has Meet(C1,C2), D1 has with {f:Integer}];

--Evaluating more complex Meet/Joint expressions causes seg fault:
--main5():Record(D1hasMeetJoin:Boolean, D1hasJoinMeet:Boolean) ==
--  [D1 has Meet(C1,Join(C1,C2)), D1 has Join(C1,Meet(C1,C2))];

   Compiling FriCAS source code from file 
      /var/lib/zope2.10/instance/axiom-wiki/var/LatexWiki/3470372493881279901-25px002.as
      using Aldor compiler and options 
-O -Fasy -Fao -Flsp -lfricas -Mno-ALDOR_W_WillObsolete -DFriCAS -Y $FRICAS/algebra -I $FRICAS/algebra
      . Use the system command )set compiler args to change these 
      options.
#1 (Warning) Could not use archive file `libfricas.al'.
"/var/lib/zope2.10/instance/axiom-wiki/var/LatexWiki/3470372493881279901-25px002.as", line 1: 
#include "fricas"
^
[L1 C1] #2 (Error) Could not open file `fricas'.

   The )library system command was not called after compilation.

f()$DM12

   DM12 is not a valid type.

-- expect False, False
main1()

   There are no library operations named main1 
      Use HyperDoc Browse or issue
                               )what op main1
      to learn if there is any operation containing " main1 " in its 
      name.

   Cannot find a no-argument definition or library operation named 
      main1 .

Comment of Ralf Hemmecke 20-Nov-2007: I would expect (false,false) for main2(), because, DM12 is not explicitly declared to be of type C1 or C2 even if its "add" domain has all the exports (except for the names C1 and C2).

-- expect True, True
main2()

   There are no library operations named main2 
      Use HyperDoc Browse or issue
                               )what op main2
      to learn if there is any operation containing " main2 " in its 
      name.

   Cannot find a no-argument definition or library operation named 
      main2 .

Comment of Ralf Hemmecke 20-Nov-2007: That main4() returns (false, false, true) should be considered a bug.