# stim match graph of circuit with distance 3 only has one node

I have a stim circuit and when I call shortest graphlike error I find that it has distance 3:

assert len(shortsurfacecode.circ.shortest_graphlike_error()) == 3

When I draw the match-graph-3d it consists of a single node and I don't understand why:

shortsurfacecode.circ.detector_error_model().diagram(type="match-graph-3d")

Here is the stim circuit:

QUBIT_COORDS(0, 2) 0
QUBIT_COORDS(1, 1) 1
QUBIT_COORDS(2, 0) 2
QUBIT_COORDS(1, 3) 3
QUBIT_COORDS(2, 2) 4
QUBIT_COORDS(3, 1) 5
QUBIT_COORDS(2, 4) 6
QUBIT_COORDS(3, 3) 7
QUBIT_COORDS(4, 2) 8
R 0 1 2 3 4 5 6 7 8
QUBIT_COORDS(2, 3) 9
R 9
QUBIT_COORDS(1, 2) 10
R 10
QUBIT_COORDS(0, 1) 11
R 11
QUBIT_COORDS(3, 0) 12
R 12
X_ERROR(0.01) 0 1 2 3 4 5 6 7 8 9 10 11 12
H 9 11
TICK
DEPOLARIZE1(0.01) 9 11 0 1 2 3 4 5 6 7 8 10 12
CX 9 7 11 1 4 10
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 9 7 11 1 4 10
DEPOLARIZE1(0.01) 0 2 3 5 6 8 12
CX 9 6 1 10 11 0
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 9 6 1 10 11 0
DEPOLARIZE1(0.01) 2 3 4 5 7 8 12
CX 9 4 3 10 5 12
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 9 4 3 10 5 12
DEPOLARIZE1(0.01) 0 1 2 6 7 8 11
CX 9 3 0 10 2 12
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 9 3 0 10 2 12
DEPOLARIZE1(0.01) 1 4 5 6 7 8 11
H 9 11
TICK
DEPOLARIZE1(0.01) 9 11 0 1 2 3 4 5 6 7 8 10 12
X_ERROR(0.01) 9 11
M 9 11
X_ERROR(0.01) 10 12
M 10 12
DETECTOR rec[-1]
DETECTOR rec[-2]
DEPOLARIZE1(0.01) 0 1 2 3 4 5 6 7 8
QUBIT_COORDS(2, 1) 13
R 13
QUBIT_COORDS(3, 2) 14
R 14
QUBIT_COORDS(4, 3) 15
R 15
QUBIT_COORDS(1, 4) 16
R 16
X_ERROR(0.01) 13 14 15 16
DEPOLARIZE1(0.01) 0 1 2 3 4 5 6 7 8
H 13 15
TICK
DEPOLARIZE1(0.01) 13 15 0 1 2 3 4 5 6 7 8 14 16
CX 13 5 8 14 6 16
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 13 5 8 14 6 16
DEPOLARIZE1(0.01) 0 1 2 3 4 7 15
CX 13 4 5 14 3 16
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 13 4 5 14 3 16
DEPOLARIZE1(0.01) 0 1 2 6 7 8 15
CX 13 2 7 14 15 8
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 13 2 7 14 15 8
DEPOLARIZE1(0.01) 0 1 3 4 5 6 16
CX 13 1 4 14 15 7
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 13 1 4 14 15 7
DEPOLARIZE1(0.01) 0 2 3 5 6 8 16
H 13 15
TICK
DEPOLARIZE1(0.01) 13 15 0 1 2 3 4 5 6 7 8 14 16
X_ERROR(0.01) 13 15
M 13 15
X_ERROR(0.01) 14 16
M 14 16
DETECTOR rec[-1]
DETECTOR rec[-2]
DEPOLARIZE1(0.01) 0 1 2 3 4 5 6 7 8
TICK
R 9 10 11 12
X_ERROR(0.01) 9 10 11 12
DEPOLARIZE1(0.01) 0 1 2 3 4 5 6 7 8
TICK
H 9 11
TICK
DEPOLARIZE1(0.01) 9 11 0 1 2 3 4 5 6 7 8 10 12
CX 9 7 11 1 4 10
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 9 7 11 1 4 10
DEPOLARIZE1(0.01) 0 2 3 5 6 8 12
CX 9 6 1 10 11 0
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 9 6 1 10 11 0
DEPOLARIZE1(0.01) 2 3 4 5 7 8 12
CX 9 4 3 10 5 12
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 9 4 3 10 5 12
DEPOLARIZE1(0.01) 0 1 2 6 7 8 11
CX 9 3 0 10 2 12
TICK
DEPOLARIZE1(0.01)
DEPOLARIZE2(0.01) 9 3 0 10 2 12
DEPOLARIZE1(0.01) 1 4 5 6 7 8 11
H 9 11
TICK
DEPOLARIZE1(0.01) 9 11 0 1 2 3 4 5 6 7 8 10 12
X_ERROR(0.01) 11
M 11
DETECTOR rec[-1] rec[-8]
X_ERROR(0.01) 12
M 12
DETECTOR rec[-1] rec[-7]
X_ERROR(0.01) 10
M 10
DETECTOR rec[-1] rec[-9]
X_ERROR(0.01) 9
M 9
DETECTOR rec[-1] rec[-12]
X_ERROR(0.01) 0 1 2 3 4 5 6 7 8
M 0 1 2 3 4 5 6 7 8
DETECTOR rec[-11] rec[-9] rec[-6] rec[-8] rec[-5]
DETECTOR rec[-15] rec[-5] rec[-2] rec[-4] rec[-1]
DETECTOR rec[-12] rec[-7] rec[-4]
DETECTOR rec[-14] rec[-3] rec[-6]
OBSERVABLE_INCLUDE(0) rec[-9] rec[-8] rec[-7]

And it's detector error model

error(0.03185674550515311954) D0 D3
error(0.04975735925829932738) D0 D5
error(0.03809865556508435641) D0 L0
error(0.03059997378373536733) D1 D2
error(0.001338700097173320998) D1 D2 D4
error(0.01911873511075361937) D1 D3
error(0.004005357180252827609) D1 D4 D6
error(0.01126977837777042371) D1 D4 L0
error(0.03874469856294735642) D1 D6
error(0.04914933380809191621) D1 L0
error(0.04425734015754984041) D2
error(0.002673815958446297981) D2 D3
error(0.002673815958446297981) D2 D3 D7
error(0.001338700097173320998) D2 D4 D6
error(0.02293841413224595796) D2 D6
error(0.02165770036624231967) D2 D6 D7
error(0.02230280153587052214) D2 D7
error(0.002673815958446297981) D2 D7 D11
error(0.04733668245378268302) D2 D11
error(0.1110374976726973273) D3
error(0.04360252789818236385) D3 D5
error(0.001338700097173320998) D3 D5 D7
error(0.03557524547345392724) D3 D6
error(0.02676856776605827937) D3 D6 D7
error(0.03432845639209641808) D3 D7
error(0.002673815958446297981) D3 D7 D9
error(0.03997966359665833247) D3 D9
error(0.1662642703886834938) D4
error(0.08897217728373547907) D4 D6 L0
error(0.004005357180252827609) D5 D6
error(0.001338700097173320998) D5 D6 D7
error(0.05570001667892007791) D5 D9
error(0.04975735925829932738) D5 D10
error(0.09227216989561401461) D5 L0
error(0.004005357180252827609) D6 D7 D8
error(0.01584743398905801709) D6 D7 D9
error(0.02867209751539220169) D6 D7 D11
error(0.001338700097173320998) D6 D7 L0
error(0.03874469856294735642) D6 D8
error(0.01584743398905801709) D6 D9
error(0.02867209751539220169) D6 D11
error(0.09985261856122865098) D6 L0
error(0.2093485274052065692) D7
error(0.006000449842759884161) D7 D8 D9
error(0.005333333333333313206) D7 D8 D11
error(0.001338700097173320998) D7 D8 L0
error(0.02101172802650804611) D7 D9
error(0.002673815958446297981) D7 D9 D11
error(0.02867209751539220169) D7 D11
error(0.02870423005727528593) D8 D9
error(0.02169031111111104776) D8 D11
error(0.04854864330815450435) D8 L0
error(0.1298754953638350251) D9
error(0.02553048530927685272) D9 D10
error(0.002673815958446297981) D9 D11
error(0.01911873511075363324) D10 L0
error(0.05632945683604310971) D11