Time Warp and Invert // Invent in hand or in your graveyard.
({G} magic symbol) ({G} magic symbol) ({U} magic symbol) ({U} magic symbol) ({U} magic symbol) ({R} magic symbol) plus eleven generic mana available each turn.
Steps
Cast Seasons Past by paying ({4} magic symbol) ({G} magic symbol) ({G} magic symbol) , returning Invert // Invent, Time Warp, and any number of cards with different mana costs to your hand and putting Seasons Past on the bottom of your library.
Cast Invent by paying ({4} magic symbol) ({U} magic symbol) ({R} magic symbol) , putting Seasons Past from your library into your hand.
Cast Time Warp by paying ({3} magic symbol) ({U} magic symbol) ({U} magic symbol) , granting you an extra turn.