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HELP OR Revised: Fran Evelyn Jul 1985 Updated: Adrian Howard Mar 1992 The infix operator -or- is used to form a "disjunction" of two expressions. For example: list = [] or hd(list) = "a" The expression <P> or <Q> is the value of <P> unless <P> is -false-, when it is the value of <Q>. In other words, unless both <P> and <Q> evaluate to -false-, the expression is true (since POP-11 treats as -true- any value which is not -false-). Normally OR will be used with *BOOLEAN expressions, when it can be treated as a logical OR operation. There is also a bitwise logical 'or' operator (||) on integers treated as sequences of "bits", see REF *NUMBERS/Bitwise details. Also see: HELP *AND --- Forming conjunctions in POP-11 HELP *BOOLEAN --- Boolean expressions and values HELP *CONDITIONALS --- Summary of POP-11 conditional statements REF *RECORDS/Booleans --- Full information on "booleans" --- C.all/help/or --- Copyright University of Sussex 1992. All rights reserved. ----------