Function check_alignment_structure 

pub fn check_alignment_structure(
    low: &InducedDag,
    high: &InducedDag,
    partition: &[Vec<NodeId>],
    high_inputs: &[NodeId],
    scope: StructureScope,
) -> Result<AlignmentStructure, QuantumError>

Definition 49’s predicates on a partition. partition[X] lists the low-level vertices of the high-level vertex X; high_inputs are the high-level input vertices, whose blocks fullness does not ask about.

Errors

QuantumError::DimensionMismatch if the partition has other than one block per high-level vertex, a block is empty, a low-level vertex is named twice or out of range, or an input is out of range. A low-level vertex in no block is allowed: π need not be onto.