Reusable query blocks can be used to simplify query building and to make them more readable.

IFC is a complex schema, and uses a lot of relation objects, traversing them can be easier by using reusable query blocks.

Elements of a reusable query block:

• IN
• Initial type query (right after IN), selects the types it can work with, basically determines that allowed IN connections
• OUT

List of reusable query blocks

• Decomposes
• Contains
• DecomposesContains
• Properties