==== VARIATION: cq=ns=test.collectionTree: $or
    $and
        a $eq 1
        x $eq 1
    $and
        b $eq 1
        y $eq 2
Sort: {}
Proj: {}
or[an[eqa,eqx],an[eqb,eqy]]||||fs

==== VARIATION: cq=ns=test.collectionTree: $and
    a $eq 1
    x $eq 1
Sort: {}
Proj: {}
an[eqa,eqx]||||fo

==== VARIATION: cq=ns=test.collectionTree: $and
    b $eq 1
    y $eq 2
Sort: {}
Proj: {}
an[eqb,eqy]||||fo

==== VARIATION: cq=ns=test.collectionTree: $and
    a $eq 1
    x $eq 1
Sort: {}
Proj: {}
an[eqa,eqx]||||fs

==== VARIATION: cq=ns=test.collectionTree: $and
    b $eq 1
    y $eq 2
Sort: {}
Proj: {}
an[eqb,eqy]||||fs

