Algorithm 6 Backward parallel transport of w(1) along α̃ = α(1 − τ)
1:	Let w̃(1) = w(1)
2:	for τ = k − 1 to 0 do
3:	$\stackrel{\sim }{w}\left(\frac{\tau }{k}\right)=\Pi \left(\stackrel{\sim }{w}\left(\frac{\tau +1}{k}\right);\alpha \left(\frac{\tau +1}{k}\right),\alpha \left(\frac{\tau }{k}\right)\right)$
4:	end for