The objective is to count the number of nodes and edges. 

Query:

g2.inject(1).union(V().has('title', 'A').aggregate('v1').union(outE().has('title', 'E1').aggregate('e').inV().has('title', 'B'),outE().has('title', 'E2').aggregate('e').inV().has('title', 'C')).aggregate('v2')).select('v1').dedup().as('sourceCount').select('e').dedup().as('edgeCount').select('v2').dedup().as('destinationCount').select('sourceCount','edgeCount','destinationCount').by(unfold().count())

[
    {
        "sourceCount": 1203,
        "edgeCount": 9922,
        "destinationCount": 9926
    }
]

But when the aggregate query is placed inside the union query to count each type of node for the inner union the results are different.

Query: 

g2.inject(1).union(V().has('title', 'A').aggregate('A').union(outE().has('title', 'E1').aggregate('E1').inV().has('title', 'B').aggregate('B'),outE().has('title', 'E2').aggregate('E2').inV().has('title', 'C').aggregate('C'))).select('A').dedup().as('ACount').select('E1').dedup().as('E1Count').select('B').dedup().as('BCount').select('E2').dedup().as('E2Count').select('C').dedup().as('CCount').select('ACount','E1Count','BCount','E2Count','CCount').by(unfold().count())

[
    {
        "vendorCount": 1203,
        "supply1Count": 4,
        "productCount": 4,
        "supplyCount": 0,
        "materialCount": 0
    }
]

The nodes and edges count doesn't match after applying a small change. Request you take a look and share your thoughts.

Thanks & Regards,

Vinayak