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| ANSI Common Lisp 12 Numbers 12.2 Dictionary of Numbers
12.2.63 logbitp | Function
  Syntax: logbitp index integer generalized-boolean Arguments and Values: index - a non-negative integer. integer - an integer. generalized-boolean - a generalized boolean. Description: logbitp is used to test the value of a particular bit in integer, that is treated as if it were binary. The value of logbitp is true if the bit in integer whose index is index (that is, its weight is 2index) is a one-bit; otherwise it is false. Negative integers are treated as if they were in two's-complement notation. Examples:
       (logbitp 1 1)  false
       (logbitp 0 1)  true
       (logbitp 3 10)  true
       (logbitp 1000000 -1)  true
       (logbitp 2 6)  true
       (logbitp 0 6)  false
  Exceptional Situations: Should signal an error of type type-error if index is not a non-negative integer. Should signal an error of type type-error if integer is not an integer. Notes:
       (logbitp k n) ==(ldb-test (byte 1 k) n)
Allegro CL Implementation Details: None.

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