Formulas and chains
A cell's “≡ Selection” button does not offer a list of abstract operations: it says what can be done with what is written in that cell.
What the menu contains
- Variable — insert a symbol already defined in the document.
- Constant — insert a physical constant with its value and unit (c, G, h, kB, NA…).
- Operation — transform: solve, differentiate, integrate, data & statistics, differential equation, optimisation, signal, visualisation, and the subject packs.
- Formula — take a formula from the glossary and place it in the cell, symbols included.
- Units — convert the quantity written there.
- Find a chain — see below.
The glossary
The Reference tab of the second screen holds 2,500 formulas, of which 2,272 are directly computable. Each entry gives the formula, its symbols, their units, and a button to insert it into the active cell. The “solvable only” checkbox restricts the search to those the engine can isolate.
Hover a formula placed in a cell to see its explanation: that is the “Formula tooltips” setting, in the document toolbar.
Find a chain
This is the least obvious and most useful function. You know some quantities, you want another, and you do not know which sequence of formulas leads there. “Find a chain” starts from what the document has already defined, walks the glossary, and proposes a path: the sequence of formulas that, applied one after another, reaches the requested quantity.
The path is written into the document, one cell per step. Nothing is hidden: each cell remains an ordinary formula, editable, with its Steps panel.
Try it
In a fresh document, define m = 1500 kg and v = 25 m/s. Then, in an empty cell, “≡ Selection” ▸ Find a chain and ask for the kinetic energy: the proposed chain places E = ½mv² and computes it. Then add h = 12 m and ask for the total mechanical energy — the chain grows by one formula.
Where to go next
The subject packs add their own operations to this same menu: see subject packs. For differential equations and optimisation, see ODEs and optimisation.