combination_check
std.linalg.combination_check · Level L1A linear combination Σ cᵢvᵢ of the rows of V with coefficients c, and whether it equals the target t, as 1 or 0: a witness that t is in the span. With integer data the check is exact.
Σ cᵢ vᵢ = t
Signature
combination_check(V: f64[k, n], coef: f64[k], t: f64[n]) → f64[n], f64[]
Structure
The function as NOVA stores it: one box per input, operation and output, and arrows that carry values. A double border marks another library function this one runs — called once, or by Scan once per element; select it to open that function.
- input
- operation
- constant
- call
- output
Verification
- Signature proven by NOVA’s shape solver, for every size.
- Equal to the reference
the weighted sum of the rows, against tin exact rational arithmetic, on all 40 test cases. - All 204 float64 results are exact: the error is zero.
- Interpreter and NumPy backend return bit-identical results.
- At float32 too: the 40 test cases rounded to float32, and 40 of them exact, with zero error.
Accuracy in detail
- correctly rounded (the float64 nearest the exact value)
- 100%
- bit-equal to the NumPy formula in float64
- 100%
- largest error, in units in the last place
- 0
Identity
sha256:8c4d5c7fc789d7257ff997aa946fb5094e2c39242378a5b2e8e94c07968493dcThe semantic hash of the graph. It changes when the program changes, and never when only its documentation does.
Control handle
- Symbol
- Ω:std.linalg.combination_check · Ω:combination_check
- Pins
sha256:5e670d8e5ce27b7d620227b4baa0980585f12dd01d1396248a90f1d8a9bdb1a6this graph and the 1 it reaches through calls- Evidence
sha256:b5bdb1fe077b75ed4b020267ed57a9d7d9acba1965b9f3871bf79d6cbd0cc895the hash of its verification record- Needs
- no capability: a pure function
Through NOVA’s control layer, the symbol launches this function only while the program still matches what it pins: a change to this graph, or to any graph it reaches, needs a migration first.