Coverage

The Coverage tab generates minimal test vectors that achieve a selected structural coverage criterion for the active expression.

Overview

Coverage analysis generates a small set of input assignments (test vectors) that, when exercised, guarantee that a particular structural criterion is met. This is used in testing to derive a test suite from a logic expression.

Coverage panel with the MC/DC strategy selected and a set of generated test vectors shown in a table. — The Coverage panel with MC/DC selected. Each row is a test vector; columns are input values and the expected output.

Coverage strategies

Strategy	Description
Branch	Each condition (atom) takes both true and false values in at least one test. Also called decision coverage.
MC/DC	Modified Condition/Decision Coverage. Each condition independently affects the outcome. Required by DO-178C and similar aerospace standards. Produces a compact test set.
Pairwise	Every pair of conditions takes all four combinations (T/T, T/F, F/T, F/F) in at least one test. Good for finding interaction defects.
Prime Implicant	Each prime implicant of the expression is covered by at least one test. Based on the QM simplification output.

Generating test vectors

Select a coverage strategy from the dropdown.
Click Generate.
The test vector table populates with the minimum set of inputs that achieve the criterion.

Reading the table

Each row is one test vector — one assignment of all input variables. Columns are the input variables (0 or 1 for booleans; predicate bucket labels for typed variables). The last column shows the expected output (0 or 1).

A summary line above the table shows how many vectors were generated and which criterion they cover.

Exporting test code

The Coverage panel includes code export buttons. Click a language tab (JavaScript, Python, C, SQL) and then Copy to get the test vectors as runnable test code or parameter tables in that language.

Limitations

Coverage is computed for the active binding's boolean atoms. Predicate atoms are treated as independent booleans — the coverage generator doesn't know that age < 18 and age >= 18 are mutually exclusive.
There is no Karnaugh map renderer. Prime implicants are listed textually, not visually on a K-map grid.
For large expressions, MC/DC vector generation can be slow.