wip
Revert "wip"

This reverts commit a4a3ab75add17ddd37876f6be36e56fddd1c6f1e.
Merge branch 'master' of github.com:karelklic/canal
Merge branch 'master' of github.com:karelklic/canal
Reduced product of arrays.

Pointer can be set to top, but value cannot be stored to a top pointer.

Fixes #134.