The following syntaxes are allowed
[[x]] -> [[edge/supports]] -> [[y]] = x supports y
[[x]] -> [[edge/supports]] -> [[y]]
[[y]] <- [[edge/supports]] <- [[x]] = x supports y
[[y]] <- [[edge/supports]] <- [[x]]
-> [[edge/supports]] -> [[y]] = parent block supports y (first arrow is optional)
-> [[edge/supports]] -> [[y]]
-> [[edge/supports]] -> = parent block supports all child blocks to this block (y) (first arrow is optional)
-> [[edge/supports]] ->
[[y]]