added example 2.1.2_3

2.1.3_3.pl

+% nacteni:
+/* ['2.1.3_3.pl']. */
+
+% vymaz predchozi deklarace member
+:- retractall(member/2).
+:- dynamic member/2.
+
+member(X,[Y|_]) :- X == Y.
+member(X,[Y|T]) :- X \== Y, member(X,T).
+
+% demonstracni vypis
+
+  % abychom se vyhli varovanim "Redefined static procedure ..."
+:- dynamic
+       write_all_X/3,
+       start/0.
+       
+write_all_X(Goal,X,Name):-
+            call(Goal),write('  '),write(Name),write(' = '),write(X),nl,fail.
+write_all_X(_,_,_).
+
+start:- 
+    write('Member - 3. varianta (efektivnejsi, taktez ne obousmerna)'),nl, nl,
+    write('Vysledek volani "member(a,[X,b,c])" je:'),nl,
+    write_all_X(member(a,[X,b,c]), X, 'X'),
+    write('No'), nl, nl,
+    write('Vysledek volani "member(a,[a,b,a]),write(ok),nl,fail"'), nl, 
+    write('  (konci pri nalezeni 1. vyskytu "a")  je:'),nl.
+?-start.
+?-member(a,[a,b,a]),write(ok),nl,fail.
+
+
+:- retractall(write_all_X/3).
+:- retractall(start/0).
+
+/* member_demo(a,[a,b,a]),write(ok),nl, fail . */
+% vrati:
+%   ok
+%   No

2.1.3_3.py

+#!/usr/bin/env python
+# encoding=utf-8 (pep 0263)
+
+def member(x, ys):
+    for y in ys:
+        if x == y:
+            return True
+    return False
+
+# demonstracni vypis
+if __name__ == "__main__":
+    print("Member - 3. varianta")
+    print('Vysledek volani member("a", ["a", "b", "a"]) je %d.' % \
+            member("a", ["a", "b", "a"]) and "True" or "False")

Makefile

@@ -2,10 +2,11 @@
 test:
 	# Testing the python files via pylint3.
 	@for FILE in *.py; do \
+		printf '%s\n' "$$FILE"; \
 		REPORT="$$(pylint3 --disable=invalid-name,missing-docstring "$$FILE" 2>&1)"; \
 		if ! [ $$? = 0 ]; then \
 			printf '%s\nThe above report is for file "%s".\n' "$$REPORT" "$$FILE"; \
 			exit 1; \
 		fi; \
-	done; \
-	printf 'All OK.\n'
+	done
+	# All OK.