Slightly modified shell-like examples in ~examples/als [animals,dc,di…

…ff,hickory+id] to make them a little more shell-like (banners; cycling in hickory+id).

examples/als/animals.pro

@@ -68,7 +68,10 @@ question(c20,'Does it swim').
 question(c21,'Is it a good flyer').
 
 animal :-
-abolish(fact/2),
+   nl,write('Simple shell for animal identification via questions'),nl,
+   write('From: How to Solve it in Prolog,'),nl,
+   write('        by Coelho, Cotta, Pereira, Lisbon, 1980'),nl,nl,
+   abolish(fact/2),
    write('Please describe the animal.'),nl,nl,
    recognition(_),
    nl,nl,

examples/als/dc.pro

@@ -38,18 +38,24 @@ module desk_calc.
     *			and evaluator.
     */
 
-   dc :- write('dc: '), 
+   dc :-
+	nl,write('Simple shell for a desk calculator'),nl,
+	write('    By Kevin Buettner'),nl,nl,
+	write('Type numeric expressions (no final . needed) plus return'),nl,
+	write('Type exit to exit from the calculator to Prolog'),nl,nl,
+	dc0.
+   dc0 :- write('dc: '), 
          readin(Line), 
 	 lexan(Line,Tokens), 
 	 parse(Tokens,Tree), 
          eval(Tree,Answer),
 	 write(Answer), nl, 
 	!, 
 	dc_again(Answer).
-   dc :- write('??'), nl, dc.
+    dc0 :- write('??'), nl, dc0.
 
    dc_again(exit) :- !, seen.
-   dc_again(_) :- dc.
+   dc_again(_) :- dc0.
 
    source(File) :-
       seeing(OldF),
@@ -112,6 +118,7 @@ module desk_calc.
     */
 
    lexan([],[]) :- !.
+   lexan(".",[]) :- !.
    lexan(InL,[Tok | Toks]) :- 
       classify(InL,RestL,Tok),
       lexan(RestL,Toks).

examples/als/diff.pro

@@ -26,8 +26,17 @@
  |      Enter stop to exit the program.
  *----------------------------------------------------------------*/
 
-
 diff :-
+   nl,write('Simple shell for a Symbolic Differentiator'),nl,
+   write('    By Keith Hughes'),nl,nl,
+   write('Type Expressions in the form'),nl,
+   write('           V:Xpr.'),nl,
+   write('where V is a variable occurring in Xpr, e.g.,'),nl,
+   write('           x:(4*x + tan(x)).'),nl,
+   write('Type   stop.   to exit.'),nl,nl,
+   diff0.
+
+diff0 :-
    write('Expression: '),
    read(T),
    diff(T).
@@ -37,10 +46,10 @@ diff(X:Expr) :-
    diff(X,Expr,T),!,
    simplify(T,Ans),
    nl,write(Ans),nl,nl,
-   diff.
+   diff0.
 diff(_) :-
    write('Illegal expression. Type stop to exit.'),nl,
-   diff.
+   diff0.
 
 diff(X,X,1) :- !.
 diff(_,Y,0) :-
@@ -67,6 +76,12 @@ diff(X,sin(Y),cos(Y)*DY) :- !,
    diff(X,Y,DY).
 diff(X,tan(Y),DY/(cos(Y)^2)) :- !,
    diff(X,Y,DY).
+diff(X,X^Z0,X^Z1) :- !,
+   integer(Z0),
+   Z0 > 1,
+   !,
+   Z1 is Z0-1,
+   diff(X,Y,DY).
 
 % simplify an expression to a very limited extent
 

examples/als/hickory.pro

@@ -13,11 +13,7 @@
  |	<Character> is <Generic Character>(<Particular Aspect>).
  *-------------------------------------------------------------------*/
 
-% When a prolog file is part of an ALS Prolog project (*.ppj), don't include
-% such consults; ususally, they will cause an error because the file to be
-% consulted isn't in the right folder; it will be listed in the project, and
-% the project search path(s) should find it:
-%:- consult(id).		% the diagnosis system
+:- consult(id).		% the diagnosis system
 
 module identify.
 

examples/als/id.pro

@@ -42,13 +42,39 @@ export identify/0.
 :- dynamic(does_not_hold/1).
 :- dynamic(trait/2).
 
- identify :-
+ identify :- 
+	header,
+	identify0.
+
+header :- nl,
+ 	write('Generic Identification by Properties shell'),nl,
+	write('   applied to Hickory Trees'),nl,
+	write('       by Ken Bowen'),nl,nl,
+	write('Enter properties characteristics of hicory trees (see hickory.pro)'),nl,
+	write('Type ''done.'' to finish inputting initial observations'),nl,nl,
+	write('Type ''exit.'' to exit the shell.'),nl,nl.
+
+ identify0 :-
         obtain_description,
         entertain_hypothesis(Identification),  	% these 2 goals are a generate
         validate(Identification),              	% and test loop
         report(Identification),
         abolish(user_observed,1),              	% clear the database of recorded
-        abolish(does_not_hold,1).          	% observations
+        abolish(does_not_hold,1),          	% observations
+	loop_or_quit.
+
+loop_or_quit
+	:-
+	nl, write('Identify another (yes. or no. ):'),
+	read(Ans),
+	loop_or_quit(Ans).
+
+loop_or_quit(yes)
+	:-
+	identify0.
+loop_or_quit(_) 
+	:- 
+	write('Bye.'),nl.
 
  obtain_description :-
         write('Observation: '),			% requires a term which occurs