Valdivia's lifting theorem for non-metrizable spaces. Preprint

The lifting theorem of Valdivia concerning (pre) compact sets and convergent (respectively, Cauchy) sequences from a quasi-(LB) space to a metrizable, strictly barrelled space is extended to a strictly larger collection of range spaces. Specifically, we assume that the range space has a sequential web structure and do not require that it be metrizable, nor strictly barrelled, and the range space need not even be barrelled. Distinguishing examples are provided that include natural constructions of range spaces connected with applications, such as the space of distributions having their wavefront sets in a specified closed cone. The same and other examples could also serve as domain spaces for the closed graph theorem of Valdivia, revealing a much wider collection of domain spaces that can be used in that result.