**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 2^*index*) 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

**Side Effects:** None.

**Affected By:** None.

**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*.

**See Also:** None.

**Notes:**

(logbitp k n) == (ldb-test (byte 1 k) n)

The following X3J13 cleanup issue,