`atom(`

`+T`)*ISO*term

`T`is an atom`atomic(`

`+T`)*ISO*term

`T`is an atom or a number`callable(`

`+T`)*ISO*`T`is an atom or a compound term`compound(`

`+T`)*ISO*`T`is a compound term`db_reference(`

`+X`)*since release 4.1*`X`is a db_reference`float(`

`+N`)*ISO*`N`is a floating-point number`ground(`

`+T`)*ISO*term

`T`is a nonvar, and all substructures are nonvar`integer(`

`+T`)*ISO*term

`T`is an integer`mutable(`

`+X`)`X`is a mutable term`nonvar(`

`+T`)*ISO*term

`T`is one of atom, number, compound (that is,`T`is instantiated)`number(`

`+N`)*ISO*`N`is an integer or a float`simple(`

`+T`)`T`is not a compound term; it is either atomic or a var`var(`

`+T`)*ISO*term

`T`is a variable (that is,`T`is uninstantiated)

`compare(`

`-C`,`+X`,`+Y`)*ISO*C is the result of comparing terms

`X`and`Y``+X`==`+Y`*ISO*terms

`X`and`Y`are strictly identical`+X`\==`+Y`*ISO*terms

`X`and`Y`are not strictly identical`+X`@<`+Y`*ISO*term

`X`precedes term`Y`in standard order for terms`+X`@>=`+Y`*ISO*term

`X`follows or is identical to term`Y`in standard order for terms`+X`@>`+Y`*ISO*term

`X`follows term`Y`in standard order for terms`+X`@=<`+Y`*ISO*term

`X`precedes or is identical to term`Y`in standard order for terms

`?T`=..`?L`*ISO*the functor and arguments of term

`T`comprise the list`L``?X`=`?Y`*ISO*terms

`X`and`Y`are unified`+X`\=`+Y`*ISO*terms

`X`and`Y`no not unify`?=(`

`+X`,`+Y`)`X`and`Y`are either strictly identical or don’t unify`acyclic_term(`

`+T`)*since release 4.3*,*ISO*term

`T`is a finite (acyclic) term`arg(`

`+N`,`+T`,`-A`)*ISO*the

`N`th argument of term`T`is`A``atom_chars(`

`?A`,`?L`)*ISO*`A`is the atom containing the character atoms in list`L``atom_codes(`

`?A`,`?L`)*ISO*`A`is the atom containing the characters in code-list`L``atom_concat(`

`?Atom1`,`?Atom2`,`?Atom12`)*ISO*Atom

`Atom1`concatenated with`Atom2`gives`Atom12`.`atom_length(`

`+Atom`,`-Length`)*ISO*`Length`is the number of characters of the atom`Atom`.`char_code(`

`?Char`,`?Code`)*ISO*`Code`is the character code of the one-char atom`Char`.`copy_term(`

`+T`,`-C`)*ISO*`C`is a copy of`T`in which all variables have been replaced by new variables`copy_term(`

`+T`,`-C`,`-G`)`C`is a copy of`T`in which all variables have been replaced by new variables, and`G`is a goal for reinstating any attributes in`C``create_mutable(`

`+Datum`,`-Mutable`)`Mutable`is a new mutable term with current value`Datum`.`dif(`

`+X`,`+Y`)`X`and`Y`are constrained to be different.`frozen(`

`+Var`,`-Goal`)The goal

`Goal`is blocked on the variable`Var`.`functor(`

`?T`,`?F`,`?N`)*ISO*the principal functor of term

`T`has name`F`and arity`N``get_mutable(`

`-Datum`,`+Mutable`)The current value of the mutable term

`Mutable`is`Datum`.`name(`

`?A`,`?L`)the code-list of atom or number

`A`is`L``number_chars(`

`?N`,`?L`)*ISO*`N`is the numeric representation of list of character atoms`L``number_codes(`

`?N`,`?L`)*ISO*`N`is the numeric representation of code-list`L``numbervars(`

`+T`,`+M`,`-N`)number the variables in term

`T`from`M`to`N`-1`sub_atom(`

`+Atom`,`?Before`,`?Length`,`?After`,`?SubAtom`)*ISO*The characters of

`SubAtom`form a sublist of the characters of`Atom`, such that the number of characters preceding`SubAtom`is`Before`, the number of characters after`SubAtom`is`After`, and the length of`SubAtom`is`Length`.`subsumes_term(General,Specific)`

*since release 4.3*,*ISO*`Specific`is an instance of`General``term_variables(`

`+Term`,`-Variables`)*since release 4.3*,*ISO*`Variables`is the set of variables that occur in`Term``unify_with_occurs_check(`

`?X`,`?Y`)*ISO*True if

`X`and`Y`unify to a finite (acyclic) term.

`?T`=..`?L`*ISO*the functor and arguments of term

`T`comprise the list`L``append(`

`?A`,`?B`,`?C`)the list

`C`is the concatenation of lists`A`and`B``keysort(`

`+L`,`-S`)*ISO*the list

`L`sorted by key yields`S``length(`

`?L`,`?N`)the length of list

`L`is`N``member(`

`?X`,`?L`)`X`is a member of`L``memberchk(`

`+X`,`+L`)`X`is a member of`L``nonmember(`

`+X`,`+L`)`X`is not a member of`L``sort(`

`+L`,`-S`)*ISO*sorting the list

`L`into order yields`S`

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