Eric Wald - 2003-05-31

More or less in order of priority.

Classes:
- Equation
- Expr(ession)
- Number
- Variable
- Sum
- Product
- Ratio
- Exponent (Root)
- Function

Signs: Positive/Negative/PlusMinus/MinusPlus
Cancellation (factors, dragging, powers->complex?)

Table: Variable assumptions
- Real
- Positive
- Negative
- Non-Zero

Peripheral classes:
- Deriv (order of variables)
- Integral
- Summation (Sigma) / Product (Pi)
- Units

User Prefs:
- names for the Imaginary Number
- Smart numeric constants

Context Menu:
- Assumptions (variable, unknown function)
- Identities (known functions)
- Conversion (units)
- Simplify / Combine / Expand
- Factor / Distribute
- Lock

Inconsistencies:
- Assumptions
- Units
- Equality checking