# Cheat sheet

Observations

 Marking Meaning Explanation \(\bullet\) task What is the exact problem to solve (a) assumption Given fact. Naming could be done differently but still using parentheses, e.g. (a), (b), ... or (1), (2),..., or (assume1), (assume2), ... [b] observation Not directly given fact, but following already known facts. Naming could be done differently but still using square brackets e.g. [a], [b], ... or [1], [2], ... or [obs1], [obs2], ... \(\Vdash\) proof Derivation or proof starts here. It separates derivation from task, assumtions and observations. It can be left out if there are no assumptions or observations. {...} motivation Every relation (equality, equivalence etc.) have to be justified. The motivation explaneds why the ralation between two terms is true. \(\square\) proven Task is completed.

# Basic structure of structured derivation

 \(\bullet\) Task(The actual task or assignment.) (a) assumption\(_{1}\) (assumption is given fact (which is true)) (b) assumption\(_{2}\) \(\vdots\) [1] {motivation or justification why abbreviation is true} observation\(_{1}\) (this new fact is followed by assumptions or previous observations) [2] {motivation or justification why abbreviation is true} observation\(_{2}\) \(\Vdash\) \(t_{0}\) (first term, begin of proof) \(=\) {motivation or justification for why \(t_{0}=t_{1}\) holds} (here could be references to assumptions or observations) \(t_{1}\) \(=\) {motivation or justification for why \(t_{1}=t_{2}\) holds } \(t_{2}\) \(\vdots\) \(t_{n-1}\) \(=\) {motivation or justification for why \(t_{n-1}=t_{n}\) holds} \(t_{n}\) (last term, could be also solution to task) \(\square\) (end of proof)

Observations

The contents of the website reflect the authors' views. The Managing Authority of the Central Baltic INTERREG IVA Programme cannot be held liable for the information published by the project partners.