Logical Boolean

NOT, AND, OR and XOR treat their operands as booleans under the integer convention: 0 is false, any non-zero value, including negative values, is true. Results are always exactly 1 or 0. Byte values, operand layouts and stack effects are in the Logical Boolean section of the opcode reference. None of these instructions touch a register.

AND, OR and XOR each pop both operands unconditionally before producing a result; there is no short-circuit evaluation the way there would be in a language with lazy boolean operators, since a stack VM has already evaluated both operand expressions and pushed both values by the time the logical instruction runs. This only matters if evaluating one of the operand expressions has a side effect, register writes, or a Coefficient Access mutation, that a short-circuiting language would skip; AND/OR/XOR never skip it.

Logical vs. Bitwise

These instructions perform boolean operations on the truthiness of a value, not on its bit pattern. For bit-pattern operations, see Bitwise (BAND, BOR, BXOR, BNOT). The two families diverge sharply outside {0, 1} inputs: NOT 5 is 0 (5 is truthy, so its logical negation is false), while BNOT 5 is ~5, the bitwise complement, a large negative number (-6). NOT on 5 returns 0, and BNOT on 5 returns -6, from the same program run against both instructions.