.Pollenfoldleaves

			fold(f, tree)

Fold over all leaves in tree in post-order iteration.

Examples

			
			
			
			node
			 
			=
			 
			

	
			Node
			(
			
			:
			table
			,
			 
			

	
			Node
			(
			
			:
			row
			,
			 
			10
			,
			 
			10
			)
			,
			 
			

	
			Node
			(
			
			:
			row
			,
			 
			10
			,
			 
			10
			)
			)
			

			
			
			Pollen
			.
			

			foldleaves
			(
			
			
			(
			x
			,
			 
			leaf
			)
			 
			->
			
			 
			x
			 
			+
			 
			
			leaf
			[
			]
			,
			 
			node
			,
			 
			0
			)