A proof of the homotopy push-out and pull-back lemma

Author:
Michihiro Sakai

Journal:
Proc. Amer. Math. Soc. **129** (2001), 2461-2466

MSC (2000):
Primary 55R70

DOI:
https://doi.org/10.1090/S0002-9939-01-05856-7

Published electronically:
January 17, 2001

MathSciNet review:
1823932

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Abstract | References | Similar Articles | Additional Information

The homotopy push-out and pull-back lemma of Iwase (1998) is a generalized version of Theorem 1.1 of Ganea (1965) and the Theorem of Rutter (1971) whose proofs were given under the simply-connectivity condition. The purpose of this paper is to give a proof in the general case.

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Additional Information

**Michihiro Sakai**

Affiliation:
Graduate school of Mathematics, Kyushu University, Fukuoka, Japan, 812-8581

Email:
msakai@math.kyushu-u.ac.jp

DOI:
https://doi.org/10.1090/S0002-9939-01-05856-7

Keywords:
Homotopy push-out,
homotopy pull-back,
NDR-pair

Received by editor(s):
December 1, 1999

Published electronically:
January 17, 2001

Communicated by:
Ralph Cohen

Article copyright:
© Copyright 2001
American Mathematical Society