. . . . . . . . "1944-05-20Z"^^ . . . . "1944Z"^^ . . . . . . "Per Enflo"@en . . . "Swedish mathematician and concert pianist" . . . . . "Per H. Enflo (Swedish: [\u02CCp\u00E6\u02D0\u0279 \u02C8e\u02D0nflu\u02D0]; born 1944) is a mathematician who has solved fundamental problems in functional analysis. Three of these problems had been open for more than forty years: The basis problem and the approximation problem and later the invariant subspace problem for Banach spaces.In solving these problems, Enflo developed new techniques which were then used by other researchers in functional analysis and operator theory for years."@en . . . . "Enflo, Per Hendrik; Enflo, P.; Enflo, P. H."@en . . . . . . . "Enflo, Per"@en . .