In basketball's Euroleague, a player who is stationary receives the ball. A few seconds after receiving the ball he steps back and after both of his feet touch the ground he shoots. Is this a travel?
Euroleague plays under FIBA Rules; in that rulebook, travelling is defined thusly:
Establishing a pivot foot by a player who catches a live ball on the playing court:
• A player who catches the ball while standing with both feet on the floor:
▬ The moment one foot is lifted, the other foot becomes the pivot foot.
▬ To start a dribble, the pivot foot may not be lifted before the ball is released from the hand(s).
▬ To pass or shoot for a field goal, the player may jump off a pivot foot, but neither foot may be returned to the floor before the ball is released from the hand(s).
Thus, if a player is stationary and receives the ball, they may pick up one foot and replace it, or may pick up both feet and replace neither foot (passing or shooting in the air), but may not pick up both feet and replace both.