FA-65534 / Ecological population dynamics / Member archive

Lotka-Volterra competition outcome: interior classification · case 04

Stable coexistence and founder control are swapped.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

c1=K1*a21-K2, c2=K2*a12-K1; any zero -> neutral; c1>0,c2<0 species1 wins at [K1,0]; c1<0,c2>0 species2 at [0,K2]; otherwise interior N1=(K1-a12K2)/(1-a12a21), N2=(K2-a21K1)/(1-a12a21), coexist if both negative, founder if both positive; None for non-positive K or negative coefficients (zero allowed).

Why this case matters

Population projections set harvest quotas, conservation status and pest-control timing; a wrong update order, boundary or rate conversion silently changes management advice.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
regression: weak competition coexist	`["founder", [75.0, 50.0]]`	`["coexist", [75.0, 50.0]]`	Failed

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