Mathematica: TIP: Protecting against computations breaking verbosely because of Null, None, Undefined. And about using Undefined as a return policy.
Mathematica: TIP: Maintain a Package library of variables for convenient units using a naming convention unit$[unitSymbol]
Mathematica: Webel: You CAN/MAY use $ in variable names and function names - just not as the first character before a Capital - and it's extremely useful. You won't get sent to Azkaban prison if do you use a $ character!
In the Webel terminology for a basic control loop there is an 'aim' value (controlled via an actuator) and a 'got' value (a value read from a sensor). The 'got' value is NOT necessarily exactly the same as the actual physical value.
SysML: When using Property::defaultValue and Property::redefinedValue to carry a "shadow hierarchy" of redefinitions across an entire system hierarchy, considering using a user-defined keyword such as «configuration» or «scenario» on each redefining Block
UML/SysML: Navigation: Try to offer a way out of a diagram (usually up a hierarchy, but possibly across) using a navigable symbol (linked to a diagram) and/or a diagram symbol. Avoid "cul-de-sacs"!
SysML: HOWTO Safely incorporate ConstraintBlock equations from a library into a project with local ValueType variants: CASE: SysPhS vs ISO-80000 ModelLibrary
Webel: SysML: Electronics: DO NOT represent a jack/socket as a dumb proxy. Imagine it can introduce some signal noise or other effect (such as buzz) to test it is a physical model.
In the Webel recipe for UML/SysML, the pattern of progressive redefinition of end Properties of Associations between progressively more specialised pairs of Blocks at the same level of abstraction is informally called a "redefinition ladder"
