2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/152051We prove that any two smooth h-cobordant simply-connected 4-manifolds can be obtained by taking two manifolds with boundary, one of which is contractible, and gluing them along the boundary via two different attaching maps.AMS-LaTeX, 12pt, psfig, amsart, 9 pages, 7 figures. Files CuspMove.ps, FingerMove.ps, Kirby.ps, S2xS2.ps, SPMXY1.ps, SPMXY2.ps, Trick.ps containing pictures are needed for compilation. They should be placed in the same directory as the main TeX fileDifferential GeometryQuantum Algebratext