duplicate

examples/dup/README.txt

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+There are two simple Turing Machine programs that duplicate a unary number.
+
+copy2 is the naïve implementation of concatenating two copy (cf.) programs.
+It requires the first bit set to 0 in order to find it back.
+(In the Rascal emulator you cannot move backwards farther than your starting position)
+
+e.g.: 0110… ⇒ 011011110…
+
+dup is a slightly less naïve but stupid implementation, which does what copy (cf.) does,
+but adds two bits on each iteration.
+It shows how Turing Machine programming does not have to be rocket science.
+
+-- Vadim Zaytsev, http://grammarware.net

examples/dup/copy2.ctur

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+MF
+J036
+J034
+W0
+MF
+J15
+MF
+J17
+W1
+MB
+J110
+MB
+J112
+W1
+MF
+J13
+MB
+J117
+MF
+J034
+W0
+MF
+J122
+MF
+J124
+W1
+MB
+J127
+MB
+J129
+W1
+MF
+J120
+MF
+J134
+

examples/dup/copy2.t_l2

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+MF
+J0 stop
+L loop
+  J0 exit
+  W0
+  REP 2 {
+    L skip
+      MF
+      J1 skip
+  }
+  W1
+  REP 2 {
+    L back
+      MB
+      J1 back
+  }
+  W1
+  MF
+  J1 loop
+L back2
+  MB
+  J1 back2
+  MF
+L loop2
+  J0 exit
+  W0
+  REP 2 {
+    L skip2
+      MF
+      J1 skip2
+  }
+  W1
+  REP 2 {
+    L back3
+      MB
+      J1 back3
+  }
+  W1
+  MF
+  J1 loop2
+L exit
+L end
+  MF
+  J1 end
+L stop
+

examples/dup/dup.ctur

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+J020
+J018
+W0
+MF
+J14
+MF
+J16
+W1
+MF
+W1
+MB
+J111
+MB
+J113
+W1
+MF
+J12
+MF
+J118
+

examples/dup/dup.t_l2

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+J0 stop
+L loop
+  J0 end
+  W0
+  REP 2 {
+    L skip
+      MF
+      J1 skip
+  }
+  W1
+  MF
+  W1
+  REP 2 {
+    L back
+      MB
+      J1 back
+  }
+  W1
+  MF
+  J1 loop
+L end
+  MF
+  J1 end
+L stop
+