# A Summary of Explanation System Question Types

Each time you query a CyclePad-derived statement, CyclePad pops up a list of questions. Here is a list of all the questions you could ask, along with the context(s) in which they appear:

If the item is a parameter parameter whose value is unknown:
What equations mention parameter?
How could I compute parameter?
Assume a value for parameter.

If the item is a parameter parameter whose derived value is numeric-value:
Why does parameter = numeric-value?
What follows from parameter = numeric-value?

If the item is a parameter parameter whose assumed value is numeric-value:
Why does parameter = numeric-value?
What follows from parameter = numeric-value?
Retract the value of parameter?
Change the value of parameter?

If the item is an equation equation,
Why does equation hold?
How has equation been used?

If the item is a component component, then for each modeling assumption true modeling assumption which holds about component and each modeling assumption unknown-modeling-assumption that is not known to be either true or false about component:
How has true-modeling-assumption been used?
When is true-modeling-assumption appropriate?
Retract the assumption true-modeling-assumption.
Assume that unknown-modeling-assumption.

If the item is a statement about the substance substance of stuff stuff:
If the substance is currently unknown:
Select a substance for stuff.
If the substance is currently known via derivation:
Why is stuff made of substance?
What follows from stuff made of substance?
If the substance is currently known via assumption:
Retract parameter as the substance of stuff.

If the item is a statement about the phase phase-parameter of stuff stuff:
If the phase is currently unknown:
Select a phase for stuff
What phase can't stuff be?
If the phase is currently known:
Why is stuff phase-parameter?
What phase can't stuff be?
If the phase is currently known via assumption:
Retract parameter as the phase of stuff.