faceSet wallSet new patchToFace movingWall faceSet leftWallSet new setToFace wallSet faceSet leftWallSet delete cellToFace moving all faceSet leftWallSet delete cellToFace right all cellSet leftCentre new zoneToCell left cellSet leftCentre add zoneToCell moving faceSet leftZone new cellToFace leftCentre both faceSet leftZone delete cellToFace left both faceSet leftZone delete cellToFace moving both faceSet leftZone add setToFace leftWallSet cellSet leftZoneMasterCells new zoneToCell left faceSet rightWallSet new setToFace wallSet faceSet rightWallSet delete cellToFace moving all faceSet rightWallSet delete cellToFace left all cellSet rightCentre new zoneToCell right cellSet rightCentre add zoneToCell moving faceSet rightZone new cellToFace rightCentre both faceSet rightZone delete cellToFace right both faceSet rightZone delete cellToFace moving both faceSet rightZone add setToFace rightWallSet cellSet rightZoneMasterCells new zoneToCell right quit