@prefix psr: . @prefix skos: . @prefix dc: . @prefix xsd: . psr: a skos:ConceptScheme . psr:-XZBJ865P-9 skos:prefLabel "nombre réel"@fr, "real number"@en ; a skos:Concept ; skos:narrower psr:-G3W62JVG-H . psr:-G3W62JVG-H skos:prefLabel "nombre positif"@fr, "positive real number"@en ; a skos:Concept ; skos:broader psr:-XZBJ865P-9 ; skos:inScheme psr: ; skos:definition """Un nombre positif est un nombre qui est supérieur à zéro, par exemple 3 ou e.
(Wikipedia, L'Encylopédie Libre, https://fr.wikipedia.org/wiki/Nombre_positif)"""@fr, """In mathematics, the set of positive real numbers,

{\\\\displaystyle \\\\mathbb {R} _{>0}=\\\\left\\\\{x\\\\in \\\\mathbb {R} \\\\mid x>0\\ ight\\\\},}

is the subset of those real numbers that are greater than zero. The non-negative real numbers,

{\\\\displaystyle \\\\mathbb {R} _{\\\\geq 0}=\\\\left\\\\{x\\\\in \\\\mathbb {R} \\\\mid x\\\\geq 0\\ ight\\\\},}

also include zero. Although the symbols

{\\\\displaystyle \\\\mathbb {R} _{+}}

and

{\\\\displaystyle \\\\mathbb {R} ^{+}}

are ambiguously used for either of these, the notation

{\\\\displaystyle \\\\mathbb {R} _{+}}

{\\\\displaystyle \\\\mathbb {R} ^{+}}

for

{\\\\displaystyle \\\\left\\\\{x\\\\in \\\\mathbb {R} \\\\mid x\\\\geq 0\\ ight\\\\}}

and

{\\\\displaystyle \\\\mathbb {R} _{+}^{*}}

{\\\\displaystyle \\\\mathbb {R} _{*}^{+}}

for

{\\\\displaystyle \\\\left\\\\{x\\\\in \\\\mathbb {R} \\\\mid x>0\\ ight\\\\}}

has also been widely employed, is aligned with the practice in algebra of denoting the exclusion of the zero element with a star, and should be understandable to most practicing mathematicians. In a complex plane,

{\\\\displaystyle \\\\mathbb {R} _{>0}}

is identified with the positive real axis, and is usually drawn as a horizontal ray. This ray is used as reference in the polar form of a complex number. The real positive axis corresponds to complex numbers

{\\\\displaystyle z=|z|\\\\mathrm {e} ^{\\\\mathrm {i} \\\\varphi },}

with argument

{\\\\displaystyle \\\\varphi =0.}