--- ais/ai-00095.txt 1999/10/08 23:41:05 1.5 +++ ais/ai-00095.txt 2000/07/15 02:29:56 1.6 @@ -1,4 +1,4 @@ -!standard RM-3.5.4 (07) 99-10-06 AI95-00095/04 +!standard RM-3.5.4 (07) 00-07-13 AI95-00095/05 !standard RM-3.5.4 (27) !class ramification 95-09-29 !status Corrigendum 2000 99-05-25 @@ -9,7 +9,7 @@ !priority High !difficulty Medium !qualifier Clarification -!subject Modular types on one's complement machines. +!subject Modular types on one's complement machines !summary @@ -24,10 +24,10 @@ !response -Consider a 36-bit one's complement machine. One should be able to -declare a 36-bit modular type. For logical operations to make sense, +Consider a 36-bit one's complement machine. One should be able to +declare a 36-bit modular type. For logical operations to make sense, the all-ones bit pattern ought to be allowed, and should compare not -equal to zero, and greater than every other bit pattern. The +equal to zero, and greater than every other bit pattern. The Implementation Permission in 3.5.4(27) is intended to allow this. On a 36-bit two's complement machine, one would declare: @@ -37,10 +37,10 @@ and T'Modulus would be 2**36, and the base range of T would be 0..2**36-1. If one says: - type T is mod 2**36-1; + type TT is mod 2**36-1; -T'Modulus is 2**36-1, and the base range of T is 0..2**36-2. -The implementation permission says that the base range of T can +TT'Modulus is 2**36-1, and the base range of TT is usually 0..2**36-2. +The implementation permission says that the base range of TT can be 0..2**36-1. This means that the all-ones bit pattern is a valid value of the type, and is not reduced via the modulus. @@ -49,7 +49,7 @@ @dinsa For a one's complement machine, the high bound of the base range of a modular type whose modulus is one less than a power of 2 may be equal to the -modulus, rather than one less than the modulus. It is implementation defined +modulus, rather than one less than the modulus. It is implementation defined for which powers of 2, if any, this permission is exercised. @dinst For a one's complement machine, implementations may support non-binary modulus

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