User:Thebigh/mysandbox: Difference between revisions
(...actually, THIS is the simplest program (:) |
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Input a number of the form 2^a 3^b |
Input a number of the form 2^a 3^b |
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<lang fractran> |
<lang fractran> |
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2/3 |
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</lang> |
</lang> |
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The output is 2^(a+b) |
The output is 2^(a+b) |
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A list of no fractions does nothing, then immediately stops. |
A list of no fractions does nothing, then immediately stops. |
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<lang fractran> |
<lang fractran></lang> |
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==Integer Sequence== |
==Integer Sequence== |
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Given the number 1 as input the following program will, as its (3n-2)th step, produce the number 2^n. |
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<lang fractran> |
<lang fractran> 2/3, 9/2, 2/1</lang> |
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{{out}}<pre> |
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2^0 |
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==Logical operations== |
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2^1 |
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It's not so hard to code up all sixteen possible two-input logic gates, so here they are. The input is 2^a 3^b where a,b are zero or one and the output is 5^1 for true and 5^0 for false. Gates that return true when all their inputs are false additionally require the flag 11 to be set as input (ie 2^a*3^b*11)- any FRACTRAN program with the number 1 as input either stops without doing anything or loops forever. |
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3^2 |
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2 x 3 |
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<lang fractran> |
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2^2 |
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5/6, 1/2, 1/3 AND gate |
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2 x 3^2 |
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5/6, 5/2, 5/3 OR gate |
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2^2 x 3 |
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1/22, 5/11 NOT gate (uses 11 as a halt flag, result of 2^a*11 is 5^not(a)) |
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2^3 |
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1/6, 5/2, 5/3 XOR gate |
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... |
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1/66, 5/22, 5/33, 5/11 NAND gate (needs 11 flag) |
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</pre> Regarding only the powers of two, we get 1,2,4,8,16, etc. |
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5/66, 1/22, 1/33, 5/11 NXOR gate (needs flag) |
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1/66, 1/22, 1/33, 5/11 NOR gate (needs flag) |
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so much for all the commonly encountered ones, but there's still another eight to go. Most are obscure and of limited utility. |
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1/2, 1/3 ZERO gate, returns false regardless of its input |
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1/6, 5/2, 1/3 "A and not B", true only if A is true and B is false |
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5/2, 1/3 A , returns the state of A regardless of B |
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1/6, 1/2, 5/3 "B and not A", true only if B is true and A is false |
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1/2, 5/3 B , returns the state of B regardless of A |
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1/66, 1/33, 5/11 "A or not B" (needs flag) |
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1/66, 1/22, 5/11 "B or not A" (needs flag) |
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5/66, 5/22, 5/33, 5/11 ONE gate, returns true regardless of its input, needs flag |
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NOT A and NOT B are omitted because the one-input NOT gate is already up there. |
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</lang> |
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==Sort three variables== |
==Sort three variables== |
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2^a 3^b 5^c |
2^a 3^b 5^c |
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<lang fractran> |
<lang fractran> |
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1001/30, 143/6, 143/10, 143/15, 13/2, 13/3, 13/5 |
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</lang> |
</lang> |
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Returns 7^A 11^B 13^C where (A,B,C) are (a,b,c) in ascending order. |
Returns 7^A 11^B 13^C where (A,B,C) are (a,b,c) in ascending order. |
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Latest revision as of 11:27, 28 November 2021
Some FRACTRAN programs in case we ever have a category for it
A+B
Input a number of the form 2^a 3^b <lang fractran> 2/3 </lang> The output is 2^(a+b)
Empty program
A list of no fractions does nothing, then immediately stops. <lang fractran></lang>
Integer Sequence
Given the number 1 as input the following program will, as its (3n-2)th step, produce the number 2^n. <lang fractran> 2/3, 9/2, 2/1</lang>
Logical operations
It's not so hard to code up all sixteen possible two-input logic gates, so here they are. The input is 2^a 3^b where a,b are zero or one and the output is 5^1 for true and 5^0 for false. Gates that return true when all their inputs are false additionally require the flag 11 to be set as input (ie 2^a*3^b*11)- any FRACTRAN program with the number 1 as input either stops without doing anything or loops forever.
<lang fractran> 5/6, 1/2, 1/3 AND gate 5/6, 5/2, 5/3 OR gate 1/22, 5/11 NOT gate (uses 11 as a halt flag, result of 2^a*11 is 5^not(a)) 1/6, 5/2, 5/3 XOR gate 1/66, 5/22, 5/33, 5/11 NAND gate (needs 11 flag) 5/66, 1/22, 1/33, 5/11 NXOR gate (needs flag) 1/66, 1/22, 1/33, 5/11 NOR gate (needs flag)
so much for all the commonly encountered ones, but there's still another eight to go. Most are obscure and of limited utility.
1/2, 1/3 ZERO gate, returns false regardless of its input 1/6, 5/2, 1/3 "A and not B", true only if A is true and B is false 5/2, 1/3 A , returns the state of A regardless of B 1/6, 1/2, 5/3 "B and not A", true only if B is true and A is false 1/2, 5/3 B , returns the state of B regardless of A 1/66, 1/33, 5/11 "A or not B" (needs flag) 1/66, 1/22, 5/11 "B or not A" (needs flag) 5/66, 5/22, 5/33, 5/11 ONE gate, returns true regardless of its input, needs flag
NOT A and NOT B are omitted because the one-input NOT gate is already up there. </lang>
Sort three variables
FRACTRAN's only data type is positive integers. Suppose (a,b,c) are the integers to be sorted. Give the following as input: 2^a 3^b 5^c <lang fractran> 1001/30, 143/6, 143/10, 143/15, 13/2, 13/3, 13/5 </lang> Returns 7^A 11^B 13^C where (A,B,C) are (a,b,c) in ascending order.