Three linear orders are needed to cover all input sets in a six-axon mouse muscle table under an exact interval model

We tested an exact structural constraint on ordered activity in one P6 mouse omohyoid source table. The table has 297 target rows and six motor axons. A target is covered if its inputs occupy consecutive positions in at least one shared linear order. We searched all 360 orders up to reversal, 64,620 pairs, and 7,711,320 triples. The best single order covered 235 targets. The best pair covered 283. Exactly three orders were needed for complete coverage, with nine complete solutions. None included the unique best single order. Keeping that order required four orders for full coverage, but three missed only one target. Removal of any 13 target rows still left a three-order requirement. A split with 148 training rows and 149 test rows gave 82.55% and 92.95% test coverage for one and two orders. Both exceeded fixed-count graph controls. Adding an order also increased coverage in those controls, so coverage gain alone did not identify another activity order. The result sets a limit on an exact interval model. It does not measure recruitment sequences or reject a graded account of activity-dependent synapse removal. We preserve complete minimum solutions, independent code, source records, figures, controls, and repeat instructions.

neuromuscular connectome · synapse elimination · motor recruitment · consecutive ones · exact enumeration · structural model · mouse development