The following is a case of a non-parasitic binding:
z is free on both sides of the β-reduction.
The following is a case of a parasitic binding:
y is free on the left-hand side but bound on the right-hand side of the β-reduction.
W. Kluge. Abstract Computing Machines. A Lambda Calculus Perspective. Springer, 2005.
Copyright © 2014 Barry Watson. All rights reserved.