diff --git a/undefined.erdplus b/undefined.erdplus
index 43ea8af..ca05c70 100644
--- a/undefined.erdplus
+++ b/undefined.erdplus
@@ -1 +1 @@
-{"version":2,"www":"erdplus.com","shapes":[{"type":"Entity","details":{"name":"Lesson","type":"regular","x":321,"y":308.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":1}},{"type":"Entity","details":{"name":"Subject","type":"regular","x":608,"y":575.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":2}},{"type":"Entity","details":{"name":"Room","type":"regular","x":293,"y":550.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":3}},{"type":"Entity","details":{"name":"Class","type":"regular","x":608,"y":209.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":4}},{"type":"Entity","details":{"name":"Teacher","type":"regular","x":982,"y":209.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":5}},{"type":"Entity","details":{"name":"Schedule","type":"regular","x":608,"y":411.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":6}},{"type":"Relationship","details":{"name":"has","isIdentifying":false,"x":794,"y":210,"slots":[{"slotIndex":0,"minimum":"","maximum":"","participation":"unspecified","cardinality":"many","role":"","entityId":4},{"slotIndex":1,"minimum":"","maximum":"","participation":"unspecified","cardinality":"many","role":"","entityId":5}],"id":7}},{"type":"Relationship","details":{"name":"has","isIdentifying":false,"x":608,"y":311,"slots":[{"slotIndex":0,"minimum":"","maximum":"","participation":"unspecified","cardinality":"one","role":"","entityId":4},{"slotIndex":1,"minimum":"","maximum":"","participation":"unspecified","cardinality":"one","role":"","entityId":6}],"id":11}},{"type":"Relationship","details":{"name":"has","isIdentifying":false,"x":795,"y":311,"slots":[{"slotIndex":0,"minimum":"","maximum":"","participation":"unspecified","cardinality":"one","role":"","entityId":5},{"slotIndex":1,"minimum":"","maximum":"","participation":"unspecified","cardinality":"one","role":"","entityId":6}],"id":14}},{"type":"Entity","details":{"name":"Day","type":"regular","x":347,"y":410.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":17}},{"type":"Relationship","details":{"name":"has","isIdentifying":false,"x":478,"y":411,"slots":[{"slotIndex":0,"minimum":"","maximum":"","participation":"unspecified","cardinality":"unspecified","role":"","entityId":17},{"slotIndex":1,"minimum":"","maximum":"","participation":"unspecified","cardinality":"unspecified","role":"","entityId":6}],"id":18}}],"connectors":[{"type":"RelationshipConnector","details":{"slotIndex":0,"id":8},"source":4,"destination":7},{"type":"RelationshipConnector","details":{"slotIndex":1,"id":9},"source":5,"destination":7},{"type":"RelationshipConnector","details":{"slotIndex":0,"id":12},"source":4,"destination":11},{"type":"RelationshipConnector","details":{"slotIndex":1,"id":13},"source":6,"destination":11},{"type":"RelationshipConnector","details":{"slotIndex":0,"id":15},"source":5,"destination":14},{"type":"RelationshipConnector","details":{"slotIndex":1,"id":16},"source":6,"destination":14},{"type":"RelationshipConnector","details":{"slotIndex":0,"id":19},"source":17,"destination":18},{"type":"RelationshipConnector","details":{"slotIndex":1,"id":20},"source":6,"destination":18}],"width":2000,"height":1000}
\ No newline at end of file
+{"version":2,"www":"erdplus.com","shapes":[{"type":"Entity","details":{"name":"Subject","type":"regular","x":981,"y":575.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":1}},{"type":"Entity","details":{"name":"Lesson","type":"regular","x":608,"y":576.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":2}},{"type":"Entity","details":{"name":"Class","type":"regular","x":608,"y":209.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":4}},{"type":"Entity","details":{"name":"Teacher","type":"regular","x":981,"y":209.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":5}},{"type":"Relationship","details":{"name":"has","isIdentifying":false,"x":794,"y":210,"slots":[{"slotIndex":0,"minimum":"","maximum":"","participation":"unspecified","cardinality":"many","role":"","entityId":4},{"slotIndex":1,"minimum":"","maximum":"","participation":"unspecified","cardinality":"many","role":"","entityId":5}],"id":7}},{"type":"Relationship","details":{"name":"has","isIdentifying":false,"x":797,"y":576,"slots":[{"slotIndex":0,"minimum":"","maximum":"","participation":"unspecified","cardinality":"one","role":"","entityId":2},{"slotIndex":1,"minimum":"","maximum":"","participation":"unspecified","cardinality":"many","role":"","entityId":1}],"id":24}},{"type":"Relationship","details":{"name":"teaches","isIdentifying":false,"x":981,"y":393,"slots":[{"slotIndex":0,"minimum":"","maximum":"","participation":"unspecified","cardinality":"many","role":"","entityId":5},{"slotIndex":1,"minimum":"","maximum":"","participation":"unspecified","cardinality":"many","role":"","entityId":1}],"id":33}},{"type":"Relationship","details":{"name":"has","isIdentifying":false,"x":608,"y":392,"slots":[{"slotIndex":0,"minimum":"","maximum":"","participation":"unspecified","cardinality":"many","role":"","entityId":4},{"slotIndex":1,"minimum":"","maximum":"","participation":"unspecified","cardinality":"one","role":"","entityId":2}],"id":36}},{"type":"Relationship","details":{"name":"has","isIdentifying":false,"x":795,"y":393,"slots":[{"slotIndex":0,"minimum":"","maximum":"","participation":"unspecified","cardinality":"many","role":"","entityId":5},{"slotIndex":1,"minimum":"","maximum":"","participation":"unspecified","cardinality":"one","role":"","entityId":2}],"id":39}},{"type":"Attribute","details":{"name":"id","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":true,"x":608,"y":103.5,"id":42}},{"type":"Attribute","details":{"name":"members","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":448,"y":134.5,"id":43}},{"type":"Attribute","details":{"name":"letter","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":386,"y":210.5,"id":44}},{"type":"Attribute","details":{"name":"grade","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":445,"y":297.5,"id":45}},{"type":"Attribute","details":{"name":"day","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":457,"y":667.5,"id":50}},{"type":"Attribute","details":{"name":"time","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":608,"y":710.5,"id":51}},{"type":"Attribute","details":{"name":"id","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":true,"x":759,"y":658.5,"id":53}},{"type":"Attribute","details":{"name":"name","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":1104,"y":652.5,"id":61}},{"type":"Attribute","details":{"name":"id","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":true,"x":1163,"y":576.5,"id":62}},{"type":"Attribute","details":{"name":"is_main_subject","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":982,"y":695.5,"id":63}},{"type":"Attribute","details":{"name":"id","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":true,"x":981,"y":80.5,"id":67}},{"type":"Attribute","details":{"name":"abbreviation","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":1112,"y":124.5,"id":68}},{"type":"Entity","details":{"name":"Room","type":"regular","x":273,"y":576.5,"isDisjointed":true,"isTotalSpecialization":true,"isSubtype":false,"supertypeEntityId":null,"id":69}},{"type":"Relationship","details":{"name":"in","isIdentifying":false,"x":441,"y":577,"slots":[{"slotIndex":0,"minimum":"","maximum":"","participation":"unspecified","cardinality":"one","role":"","entityId":69},{"slotIndex":1,"minimum":"","maximum":"","participation":"unspecified","cardinality":"one","role":"","entityId":2}],"id":70}},{"type":"Attribute","details":{"name":"has_piano","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":273,"y":466.5,"id":73}},{"type":"Attribute","details":{"name":"number","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":100,"y":576.5,"id":74}},{"type":"Attribute","details":{"name":"type","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":273,"y":687.5,"id":75}},{"type":"Attribute","details":{"name":"name","isDerived":false,"isMultivalued":false,"isOptional":false,"isComposite":false,"isUnique":false,"x":1174,"y":209.5,"id":80}}],"connectors":[{"type":"RelationshipConnector","details":{"slotIndex":0,"id":8},"source":4,"destination":7},{"type":"RelationshipConnector","details":{"slotIndex":1,"id":9},"source":5,"destination":7},{"type":"RelationshipConnector","details":{"slotIndex":0,"id":25},"source":2,"destination":24},{"type":"RelationshipConnector","details":{"slotIndex":1,"id":26},"source":1,"destination":24},{"type":"RelationshipConnector","details":{"slotIndex":0,"id":34},"source":5,"destination":33},{"type":"RelationshipConnector","details":{"slotIndex":1,"id":35},"source":1,"destination":33},{"type":"RelationshipConnector","details":{"slotIndex":0,"id":37},"source":4,"destination":36},{"type":"RelationshipConnector","details":{"slotIndex":1,"id":38},"source":2,"destination":36},{"type":"RelationshipConnector","details":{"slotIndex":0,"id":40},"source":5,"destination":39},{"type":"RelationshipConnector","details":{"slotIndex":1,"id":41},"source":2,"destination":39},{"type":"Connector","details":{"id":46},"source":42,"destination":4},{"type":"Connector","details":{"id":47},"source":43,"destination":4},{"type":"Connector","details":{"id":48},"source":44,"destination":4},{"type":"Connector","details":{"id":49},"source":45,"destination":4},{"type":"Connector","details":{"id":57},"source":50,"destination":2},{"type":"Connector","details":{"id":58},"source":51,"destination":2},{"type":"Connector","details":{"id":59},"source":53,"destination":2},{"type":"Connector","details":{"id":64},"source":62,"destination":1},{"type":"Connector","details":{"id":65},"source":61,"destination":1},{"type":"Connector","details":{"id":66},"source":63,"destination":1},{"type":"RelationshipConnector","details":{"slotIndex":0,"id":71},"source":69,"destination":70},{"type":"RelationshipConnector","details":{"slotIndex":1,"id":72},"source":2,"destination":70},{"type":"Connector","details":{"id":76},"source":75,"destination":69},{"type":"Connector","details":{"id":77},"source":73,"destination":69},{"type":"Connector","details":{"id":78},"source":74,"destination":69},{"type":"Connector","details":{"id":81},"source":67,"destination":5},{"type":"Connector","details":{"id":82},"source":68,"destination":5},{"type":"Connector","details":{"id":83},"source":80,"destination":5}],"width":2000,"height":1000}
\ No newline at end of file