Glossary of Terms
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[action] The then-part of a production that is executed when the production     
     successfully matches working memory.  The normal action is to create a
     preference for a working memory element.
     
[attribute] The second symbol in an augmentation.  It represents a relation     
     of property of an object.  Each augmentation has a single attribute. An
     object can have more than one values for an attribute.  For example: ...
     ^attr val1 val2 ....
     
[augmentation] A working-memory element consisting of three fields:     
     identifier, attribute, and value.  A group of augmentations that share a
     common identifier are called an object.
     
[backtracing] A dependency analysis that determines the conditions of a     
     chunk.
     
[chunk] A production learned by Soar.      
     
[conditions] The collection of statements in the if-side of a production     
     that are to be matched against the contents of working memory.
     
[condition] A single condition within a production's condition side.     
     
[conflict impasse] An impasse where two or more objects are better     
     than each other.
     
[conjunctive test] A collection of tests in the condition of a production     
     that must all be satisfied for the production to fire.  They are
     delimited by { }.
     
[conjunctive negation] A negated condition, comprised of a conjunction of two     
     or more condition elements.
     
[constraint-failure] An impasse where there are conflicting     
     necessity preferences on which object to choose.
     
     
[context object] The value of a context slot, which is an     
      goal, problem-space, state, or operator.
     
[context stack] A stack of goal contexts.     
     
[default knowledge] The set of productions that are always loaded     
     with a task and provide default responses to impasses.
     
[expensive chunk] A chunk whose conditions are combinatorially     
     expensive to match against working memory.  This can slow down rather
     than speed up Soar's execution after learning.
     
[goal context] A goal and its current problem space, state, and     
     operator.  
     
[identifier] A symbol that identifies an object.  Also, the first     
     symbol in an augmentation.  For example: (identifier ^attr val)
     
[impasse] A situation where problem solving is unable to make progress.     
     This is detected automatically by the decison procedure.  There are four
     types of impasses: tie, conflict, no-change, constraint-failure.
     
[instantiation] The set of working-memory elements that satisfy the     
     production.
     
[justification] A structure built to provide support for the result of a     
     subgoal.  It is essentially the instantiation of the chunk that would be
     built for the result.
     
[linked] The contents of working memory and preference memory, and the     
     conditions of productions must be linked to a goal context through the
     identifiers and values of the tested augmentations and preferences. The
     value of an augmentation provides a link if the identifier is already
     linked to a goal identifier.  The actions of a production must be linked
     to the conditions.
     
[multi-valued attribute] An augmentation with multiple values.  For     
     example, {^cells c1 c2 c3 ... c9}.
     
     
[negated condition] Single condition elements that are preceded with a     
     dash "-" or groups of condition elements surrounded by curly braces {{}}
     and a single dash.  Signifies a test for the *absence* of those patterns
     in working memory.
     
[no-change impasse] An impasse where the elaboration phase     
     runs to quiescence, and the decision procedure does not find a change to
     make to the context stack.
     
     
[object] One or more working-memory elements with the same     
     identifier.  Generally written as a list beginning with the identifier,
     and followed by augmentations.
     
[overgeneral chunk] A chunk whose conditions do not sufficiently     
     constrain the match, and which therefore fire in situations where they
     should not.
     
[predicates] Tests that can be included in the conditions of     
     productions, including <> (not equal), <=> (not same type), > (greater
     than), >= (greater than or equal), <= (less than or equal), < (less than
     or equal).
     
[preference] A data structure created by the action of a     
     production that asserts the relative or absolute worth of a value for an
     augmentation.
     
[problem space] The entire collection of states and operators     
     used to find a solution to the problem or complete the task at hand.
     
[production] Conditional statements that form the entire     
     production system.  If the conditions of a production are matched, or
     are true, then the actions of a production will be performed.
     
[refinement] A preference created by a production that is not an     
     operator creation, operator modification, or operator application
     production.  A refinement will be retracted when the production that
     created it no longer matches working memory.
     
[support] Determines the persistence of preferences in preference     
     memory.  There are two types of support: I-support and O-support.
     
[time-tag] A unique number assigned to a working-memory element.  These are     
     generated in sequential order as working-memory elements are created.
     Watch level 1 prints out the time-tags of the working-memory elements
     matched, created and removed.  The print function will print out
     working-memory elements given a time-tag.
     
     
[value] The third field of an augmentation.  It is associated with the     
     attribute of the augmentation.  A value can be a constant or the
     identifier of another augmentation.
     
[working memory] The repository for all working-memory elements.     
     
[working memory element] A single unit of data within working memory,     
     either an augmentation or an acceptable preference for a context slot.