Yes it is correct, this is how an instance (indep) travels from the tree's root-node all the way down the tree (mod). However, I realized that is not necessary to consider "number and new_node_id" on the SORT operation.
The model gotten from LearnC is a binary tree forest, each split node is compound by 2 records: low_equal branch (high_fork = 0) and high branch (high_fork = 1), both with the same threshold value.
Indep dataset is distributed by id, thus all instance's attribute values are located in the same cluster-node (Ind).
Distributed instance data (Ind) is joined with the tree's model (mod) by "number and a fuzzy condition: 
- in order to identify every single possible instance-step inside the tree, it is necessary to pair the datasets by attribute (number) and the fuzzy condition "RIGHT.high_fork = IF(LEFT.value > RIGHT.value, 1, 0)".
- attribute values (LEFT.value) are used to determine which split-branch to follow when an instance gets one split node: less or equal results go to low_equal branches and greater ones go to high branches.
The JOIN operation, join0, returned all possible decisions (one answer for each instance at every split node). However, an instance must travel down from tree's root node (level 1) to a leaf node (a node level increase is considered as travel down, basically all tree graphs are displayed up side down ). I'm using "sort0" and "dedup0" to clean the path:
- SORTing join0 LOCALLY by group_id, id, level and node_id, path information for every instance (id) at each tree (group_id) is put together and ordered by level and node_id. (** number and new_node_id are not necessary to do the trick **).
- for every instance at each tree, dedup0 keeps only records from sort0 that follow the following rule "If two consecutive records have the same (group_id, id), discard the RIGHT record when LEFT.new_node_id is not equal to RIGHT.node_id", making sure that the path must follow the link LEFT.new_node_id = LEFT.node_id.
Finally, dedup1 keeps the record from all instance travels. The value of new_node_id indicates the final node reached by the instance.
Sum up, sorting and then deduping the data based on different attributes is correct in this case, "number and new_node_id" will be delete from "sort0" because they don't contribute to the result.