# add.tur: classical example of the sum of two numbers.
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# Tape format: "011...11011...110" where the number of 1's in both sets
# are the numbers to sum.
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0 0 0 r 1 Move to the right until you find the central zero.
1 1 1 r 1
1 0 1 r 2 Substitute the central zero for a one.
2 1 1 r 2 Search for the las zer.
2 0 _ l 3 Change it for a _lanc.
3 1 0 r 3 Change the last one for a zero (obtaining then the sum of the original numbers).