is_topology

std.topology.is_topology · Level L3

Whether a finite family of subsets is a topology, as 1 or 0: all four axioms of topology_axioms hold.

[all topology axioms]

Signature

is_topology(tau: f64[m, 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.

tauf64[m, n]topology_axiomsa1Multiplyp1Multiplyp2Multiplytopologytopologyf64[]
  • 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

Calls
Called by
—
sha256:9a5cda3e8922ff9b850b0db8a20e9054b74684caa307ca6adf9285cf40bf4952

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

Control handle

Symbol
Ω:std.topology.is_topology · Ω:is_topology
Pins
sha256:90c81d6d145fd7bae50b9cf49e3150bb54a8747aacb8928934fd069980a431ecthis graph and the 1 it reaches through calls
Evidence
sha256:6f0a26f486e1cc45e0fea309896050947ad0cc5f61d39d8d76d84c1f67db6b92the 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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