.DEMO


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F3
RT
RT
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+This demo describes the game mode of the Roo environment. Press any key.
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+Press a key every time you have read a message in this line.
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+The condition of a game: We are given pictures drawn by an invisible program.
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+We have to create a program drawing the same pictures.
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+THE MAIN IDEA: Every concept may be taught by using a series of games.
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+The following game shows the concept of a program.
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+This particular game is very easy. Even 4-5 years old kids may play it.
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^T
BS BS BS BS BS BS BS BS BS BS
:linear
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+The pattern program has been loaded into the "black box".
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+The number of hearts reflects the level of complexity of the game.
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+You are being given the condition of the game, that is the initial positions...
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+...and the corresponding pictures. The red arrow shows the initial position.
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+Press F1 to look at the resulting picture.
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F1
+The condition of game is given. It is easy to tell that...
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+...the pattern program consists of 4 commands: TURN, TURN, HOP, STEP.
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+So here is the program:
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+
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F3
F3
F1
F2
+Is it a solution? You may check it. Press TAB to switch the F-keys line.
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TB
+Press F6 and then F2 to find if this solution is correct.
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F6
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A F6 F2$
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+OK, this game was too easy. The next one will be more complicated.
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+It was solved by 9 years old kids at the second lesson devoted to branchings.
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^T
BS BS BS BS BS BS BS BS BS
:branch
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+The purpose of this game is to show the concept of a branching.
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+There are two initial positions (the first one you may see now) and...
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+...two pictures. One has to create a program which will draw...
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+...the first (the second) picture starting at the first (the second) position.
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+Press F1 to see the first picture.
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F1
+Now press F1 twice to see the next initial position and the next picture.
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F1
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F1
+The condition of the problem is given. Let us try to solve it.
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+Suppose we are not so smart as those 9 years old guys and made a wrong program.
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UP UP UP UP UP UP UP 
^Y ^Y ^Y ^Y ^Y ^Y ^Y 
:if Roo can move forward then\
:turn\
:turn\
:turn\
:hop\
:step\
:turn\
:step\
:step\
:turn\
:step\
:otherwise\
:turn\
:step\
:step\
:the end of branching\
+Let us try this program. Put Roo at the first initial position. 
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+For this purpose we have to recall the condition of the game. Press F6 and F1. 
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F6
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A F6 F1
+This is the first initial position. We do not need a result now, so press ESC.
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+Now press F1 to carry out our program.
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F1
+Yes, it is not a square. Thus there is a bug in our program. Where is it?
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+There are two possibilities to get a hint. 
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+First, you may look how the "pattern" program works. Just press F6 and then F3.
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F6
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A F6 F3$
+...and from the other position.
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F1
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+This hint "costs" one heart. 
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+Another possibility is to compare our program with the pattern one. 
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+In order to compare press F6 and then F4. 
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F6
+You will see the "pattern" Roo in the left pen and our Roo in the right one.
F6 
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A F6 F4$
+Each comparison "costs" two hearts.  
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#
+You may solve the problem yourself now. Good bye.
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