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-- Programmed by Jedidiah Barber
-- Licensed under the Sunset License v1.0
-- See license.txt for further details
-- Taken from Algebra 1, Glencoe/McGraw-Hill, New York, New York, 1998
-- pg. 411, Problem 56:
-- There are 8 houses on McArthur St, all in a row. These houses
-- are numbered from 1 to 8.
-- Allison, whose house number is greater than 2, lives next door
-- to her best friend, Adrienne. Belinda, whose house number is
-- greater than 5, lives 2 doors away from her boyfriend, Benito.
-- Cheri, whose house number is greater than Benito's, lives
-- three doors away from her piano teacher, Mr. Crawford. Daryl,
-- whose house number is less than 4, lives 4 doors from his
-- teammate, Don.
-- Who lives in each house?
with
Ada.Text_IO,
Kompsos.Math,
Kompsos.Pretty_Print;
procedure Houses is
package TIO renames Ada.Text_IO;
-- Only using the Math subpackage so no need for anything fancier than Boolean.
package BKomp is new Kompsos (Boolean);
use BKomp;
package Math is new BKomp.Math (False, True);
-- Since the following subprograms are procedures, they cannot be used
-- with Conjunct. Some don't take a Term_Array for inputs either.
-- But that's alright because we aren't conjuncting things here anyway.
procedure Unique
(This : in out Goal;
Inputs : in Term_Array) is
begin
if Inputs'Length <= 1 then
return;
end if;
for Index in Inputs'First + 1 .. Inputs'Last loop
This := Disjunct
(Math.LT (This, Inputs (Inputs'First) & Inputs (Index)),
Math.GT (This, Inputs (Inputs'First) & Inputs (Index)));
end loop;
Unique (This, Inputs (Inputs'First + 1 .. Inputs'Last));
end Unique;
procedure Within_Range
(This : in out Goal;
Value, Low, High : in Term) is
begin
Math.GTE (This, Value & Low);
Math.LTE (This, Value & High);
end Within_Range;
procedure Doors_From
(This : in out Goal;
Person_A, Diff, Person_B : in Term) is
begin
This := Disjunct
(Math.Add (This, Person_A & Diff & Person_B),
Math.Subtract (This, Person_A & Diff & Person_B));
end Doors_From;
One : constant Term := Math.Build (1);
Two : constant Term := Math.Build (2);
Three : constant Term := Math.Build (3);
Four : constant Term := Math.Build (4);
Five : constant Term := Math.Build (5);
Six : constant Term := Math.Build (6);
Seven : constant Term := Math.Build (7);
Eight : constant Term := Math.Build (8);
Relation : Goal := Empty_Goal;
Allison : constant Term := Relation.Fresh;
Adrienne : constant Term := Relation.Fresh;
Belinda : constant Term := Relation.Fresh;
Benito : constant Term := Relation.Fresh;
Cheri : constant Term := Relation.Fresh;
Mr_Crawford : constant Term := Relation.Fresh;
Daryl : constant Term := Relation.Fresh;
Don : constant Term := Relation.Fresh;
Result : State;
begin
Within_Range (Relation, Allison, Three, Eight);
Within_Range (Relation, Adrienne, One, Eight);
Within_Range (Relation, Belinda, Six, Eight);
Within_Range (Relation, Benito, One, Eight);
Within_Range (Relation, Cheri, Two, Eight);
Within_Range (Relation, Mr_Crawford, One, Eight);
Within_Range (Relation, Daryl, One, Three);
Within_Range (Relation, Don, One, Eight);
Unique (Relation, Allison & Adrienne & Belinda & Benito & Cheri & Mr_Crawford & Daryl & Don);
Doors_From (Relation, Allison, One, Adrienne);
Doors_From (Relation, Belinda, Two, Benito);
Doors_From (Relation, Cheri, Three, Mr_Crawford);
Doors_From (Relation, Daryl, Four, Don);
Math.GT (Relation, Cheri & Benito);
Result := Relation.Run;
TIO.Put_Line ("Allison:" & Integer'Image (Math.Value (Allison.Resolve (Result))));
TIO.Put_Line ("Adrienne:" & Integer'Image (Math.Value (Adrienne.Resolve (Result))));
TIO.Put_Line ("Belinda:" & Integer'Image (Math.Value (Belinda.Resolve (Result))));
TIO.Put_Line ("Benito:" & Integer'Image (Math.Value (Benito.Resolve (Result))));
TIO.Put_Line ("Cheri:" & Integer'Image (Math.Value (Cheri.Resolve (Result))));
TIO.Put_Line ("Mr Crawford:" & Integer'Image (Math.Value (Mr_Crawford.Resolve (Result))));
TIO.Put_Line ("Daryl:" & Integer'Image (Math.Value (Daryl.Resolve (Result))));
TIO.Put_Line ("Don:" & Integer'Image (Math.Value (Don.Resolve (Result))));
end Houses;
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