## Subjective Logic Operators Demo |
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: bbelief |
is the belief that the proposition is true. |

: ddisbelief |
is the belief that the proposition is false. |

: uuncertainty |
is belief that is neither committed to truth nor falsehood of the proposition. |

: abase rate |
is the prior probability of the proposition in the absence of specific belief or disbelief. The default value is the relative atomicity, i.e. 0.5 for a binary state space containing the proposition and its negation. |

Opinions can be visualized on opinion triangles as shown below. A blue point represents a (*b*,*d*,*u*) triple.
The *b*,*d*,*u*-axes run from one side to the opposite vertex indicated by the letters b, d and u.
For example, a strong positive opinion is represented by a point towards the bottom right b-vertex.
The base rate 'a' is shown as a pointer along the base line, and the projected probability 'P' is formed by projecting the opinion point onto the base, in parallel with the base rate 'director' line.

Try various subjective logic operators in action below. You can also try the opinion visualisation demo, and the trust network demo that uses trust discounting and cumulative fusion operators for analysing a simple trust network.

The mathematical details of each operator are described in the book on subjective logic. For a summary of the operators see the subjective logic page on Wikipedia.

The following operators are implemented in the demo below:
**Addition**, **Subtraction**, **Complement**, **Multiplication**, **Comultiplication**, **Division**, **Codivision**, **Uncertainty maximization**, **Trust discounting**, **Deduction**, **Subjective Bayes' theorem**, **Abduction**, **Constraint fusion**, **Cumulative fusion**, **Averaging fusion**, **Weighted fusion**, and **Unfusion**.

Choose an operator using the selector at the top left in the frame below. Then left-click and drag the opinion points and the base rate pointers on the left triangles to set the argument opinions. The computed result opinion is shown on the right-most triangle.

*JavaScript design by Gaëtan Bouguier. Original design concept by Simon Pope.*

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Last updated: 15 August 2017.