Arbor Elf + Freed from the Real + Fertile Ground

Arbor Elf
Freed from the Real
Fertile Ground

Requires
All permanents on the battlefield. Freed from the Real attached to Arbor Elf. Fertile Ground attached to a Forest you control.
Steps
  1. Activate Arbor Elf by tapping it, untapping the enchanted forest
  2. Activate the Forest by tapping it, adding ug
  3. Activate Freed from the Real by paying u, untapping Arbor Elf
  4. Repeat
Results
Infinite green mana.