arangosh> db._explain("FOR v,e,p IN 1..3 OUTBOUND 'circles/A' GRAPH 'traversalGraph' LET localScopeVar = RAND() > 0.5 FILTER p.edges[0].theTruth != localScopeVar RETURN v._key", {}, {colors: false});
Query string:
 FOR v,e,p IN 1..3 OUTBOUND 'circles/A' GRAPH 'traversalGraph' LET localScopeVar = RAND() > 0.5 
 FILTER p.edges[0].theTruth != localScopeVar RETURN v._key

Execution plan:
 Id   NodeType          Est.   Comment
  1   SingletonNode        1   * ROOT
  2   TraversalNode        1     - FOR v  /* vertex */  , e  /* edge */  , p  /* paths */  IN 1..3  /* min..maxPathDepth */  OUTBOUND 'circles/A' /* startnode */  GRAPH 'traversalGraph'
  3   CalculationNode      1     - LET localScopeVar = RAND() > 0.5   /* simple expression */
  4   CalculationNode      1     - LET #4 = p.`edges`[0].`theTruth` != localScopeVar   /* simple expression */
  5   FilterNode           1     - FILTER #4
  6   CalculationNode      1     - LET #6 = v.`_key`   /* attribute expression */
  7   ReturnNode           1     - RETURN #6

Indexes used:
 none

Traversals on graphs:
 Id   Depth   Vertex collections   Edge collections   Filter conditions
  2   1..3    circles              edges              

Optimization rules applied:
 Id   RuleName
  1   move-calculations-up
  2   move-calculations-down


arangosh> db._explain("FOR v,e,p IN 1..3 OUTBOUND 'circles/A' GRAPH 'traversalGraph' FILTER p.edges[0].label == 'right_foo' RETURN v._key", {}, {colors: false});
Query string:
 FOR v,e,p IN 1..3 OUTBOUND 'circles/A' GRAPH 'traversalGraph' FILTER p.edges[0].label == 'right_foo' 
 RETURN v._key

Execution plan:
 Id   NodeType          Est.   Comment
  1   SingletonNode        1   * ROOT
  2   TraversalNode        1     - FOR v  /* vertex */  , e  /* edge */  , p  /* paths */  IN 1..3  /* min..maxPathDepth */  OUTBOUND 'circles/A' /* startnode */  GRAPH 'traversalGraph'
  3   CalculationNode      1     - LET #3 = p.`edges`[0].`label` == "right_foo"   /* simple expression */
  4   FilterNode           1     - FILTER #3
  5   CalculationNode      1     - LET #5 = v.`_key`   /* attribute expression */
  6   ReturnNode           1     - RETURN #5

Indexes used:
 none

Traversals on graphs:
 Id   Depth   Vertex collections   Edge collections   Filter conditions
  2   1..3    circles              edges              `Path`.`edges`[0] -> e.`label` == "right_foo"

Optimization rules applied:
 Id   RuleName
  1   move-calculations-up
  2   move-filters-up
  3   move-calculations-up-2
  4   move-filters-up-2
  5   merge-traversal-filter