Tim Griffiths wrote:
Err...nope. At least, I hope not. If I brought my back hand that far behind me in iriminage I'd hope uke would have me flat on the mat with a couple of seconds. Plus iriminage at waist height (as gedan gaeshi) is less effective then at, say, neck/head height. Its not even the same principle, as the initial retraction is much more linear in the gaeshi.
Actually Tim, Budochild is correct.
Visualise a yokomen attack against gyaku hamni posture, counter the yokomen by entering with a strike to the face.
Thats your Tsuki part.
From here withdraw to an offline position and take control of ukes attacking arm with your striking hand.
That is effectively the Gedan part.
Now sweep this arm up and step forward into irimi nage postion. Irimi nage omote is possible from here and you've pretty much moved in the the same manner as tsuki gedan gaeshi.
Its also exactly the same as a lead hand jab to the face followed by a rear leg roundhouse kick to the thigh or knee.
As you say...principles are most important. As bruce Lee would say 'no fixed forms'.