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string in a set of n persistent strings, say the binary representations of the numbers 1 through n,is prefixed by the same string, say I,which uniquely indicates that the strings are to serve as the data base for the random number generator. When the state S(t)contains these strings and the signal (string) J,the broadcast unit |
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then accomplishes the task, with J signaling that the sample-taking procedure is to be initiated, and I1 indicating the result. Simple, nonuniform random variables can be approximated by making multiple copies of numbers in the base (so that their proportions approximate the nonuniform distribution). More complex distributions can be handled by using the general computational powers of sets of broadcast units in conjunction with the above procedure. |
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3. The object is to generate a sample as in (2) but without replacement (the number drawn is deleted from the data base tagged by I). To accomplish this a second broadcast unit is added to the one in (2) giving |
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The second unit deletes the string just selected from the data base since just that string is uniquely prefixed with I1 by the first broadcast unit. |
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4. A particular substring I0 is to serve as a special punctuation mark and the object is to cleave an arbitrary string at the first (ith) occurrence of I0 (if it occurs) in that string. To accomplish this let I be a prefix identifying the string to be cleaved, let I1 identify the component to the left of I0 after the cleavage and let I2identify the component to the right (including I0). The following set of broadcast units accomplishes the cleavage at the first occurrence of I0: |
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  | Signal J1 initiates the process and the string which equal" to the string to be cleaved. | | |  | A test is made to see if the punctuation I0 is a prefixof the current version of the right component. If so signal J2 is emitted, indicating that cleavage has been accomplished. Otherwise J3 is emitted, indicating that the test should be repeated one place to the right. |  | | | |  | Signal J6 indicates that the punctuation test failed exactly two time-steps ago. |  | |  | |
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