is_group

std.algebra.is_group · Level L3

Whether a finite Cayley table is a group, as 1 or 0: all four axioms of group_axioms hold.

[closure ∧ associativity ∧ identity ∧ inverses]

Signature

is_group(T: i64[n, 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.

Ti64[n, n]group_axiomsclosedMultiplyg1Multiplyg2Multiplygroupgroupf64[]
  • input
  • operation
  • constant
  • call
  • output

Verification

  • Signature proven by NOVA’s shape solver, for every size.
  • Equal to the reference all four axioms in exact rational arithmetic, on all 40 test cases.
  • All 40 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

sha256:4670a6319e0ad3b0813648e85af9be6df9bfbbdaa683116a6507b604ed41289f

The semantic hash of the graph. It changes when the program changes, and never when only its documentation does.

Control handle

Symbol
Ω:std.algebra.is_group · Ω:is_group
Pins
sha256:e5cd0c78da2c8b866e33ca6f5abf6db6ef769c9a03da4d5a08b732166c8b8be9this graph and the 1 it reaches through calls
Evidence
sha256:83390173c16290a3153bef4b56c08c9e4c385e0e604c61d6ff715bc7707ee0d5the 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.

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