Models & Notation:		Information Models - Spatial Notations
modelling systems (introduction)
system models (dynamics graphs)
information models: spatial
associative networks

Combinatorics

Carroll's bilateral diagrams/trilateral diagrams - visualize the possible combinations of, respectively, two or three Boolean variables. Bilateral diagram is Lewis Carroll's device to represent the situation in which objects are considered that may or may not have two properties. Trilateral diagrams were invented by Lewis Carroll for syllogisms [history entry for Carroll]: Syllogism interpretation of bilateral diagrams Syllogism interpretation of trilateral diagrams

Logical expressions
Peirce's existential graphs - a notation for logical expressions (based on negation & conjunction) [JCM]
conjunction = a and b				nand = not (a and b)
nor = not (a or b) = not a and not b				disjunction = a or b = not (not a and not b)
inhibition = a and not b				implication = a => b = not (a and not b)

Class inclusion diagrams
navigation bar: Class Inclusion relations inclusion diagrams in information engineering arrows in class diagrams Venn diagrams (or Euler circles) - depict relationships between sets spatially; originally used to visualize logical inclusions First used by Euler: «If justice is to be served, we should call [a Venn diagram] an "Euler diagram."» - History entries for Euler and Venn E.g. Venn (Euler) diagrams for logical expressions E.g. Venn (Euler) diagrams for subtyping: [T Halpin: UML Data Models from an ORM Perspective: Part Six; Conceptual Modeling 6; Dec 1998] and [T Halpin: Subtyping: conceptual and logical issues; Database Newsletter 23/6]
.---------------------. .--------. |_____InProgress______| | Broken |   | | `--------' | .-------. .------. | .--------. | | Empty | | Full | | | Sealed | | `-------' `------' | `--------' `---------------------' states of bottles at bottler In Statechart, the generalisation relation between sub- and superstates (a nesting order) is shown as by nesting substates in superstates. Usually the state transitions are also shown. For a full diagram see system models.