LEGAL PRINCIPLE: Whoever, intending to take dishonestly any movable property out of the possession of any person without that person's consent, moves that property with an intention to take it, is said to commit theft.
FACTS: Y cuts down a tree on Z's ground with the intention of dishonestly taking it out of Z's possession without Z's consent. Y could not take away the tree.
Y has committed theft.
As soon as Y severed tree belonging to Z from Z's land the tree became subject of theft. As soon as Y did an act to take away a property belonging to Z from his possession he has committed theft. Actual taking away of the property is not a necessary and mere change in property with the intention of taking it away is theft.
therefore, even though Y is yet to take the tree out of Z's possession he has committed theft as soon as he severed the tree from Z's land.