# Notations I

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$\mathbf{I}$
unit matrix; Common Notations and Definitions
$\Im$
imaginary part; 1.9.2
$I^{\NVar{\alpha}}$
fractional integral; 1.15.47
$I(\NVar{\mathbf{m}})$
general elliptic integral; §19.29(ii)
$\widetilde{I}_{\NVar{\nu}}\left(\NVar{x}\right)$
modified Bessel function of the first kind of imaginary order; 10.45.2
$I_{\NVar{\nu}}\left(\NVar{z}\right)$
modified Bessel function of the first kind; 10.25.2
${\mathsf{i}^{(1)}_{\NVar{n}}}\left(\NVar{z}\right)$
modified spherical Bessel function; 10.47.7
${\mathsf{i}^{(2)}_{\NVar{n}}}\left(\NVar{z}\right)$
modified spherical Bessel function; 10.47.8
$I_{\NVar{x}}\left(\NVar{a},\NVar{b}\right)$
incomplete beta function; 8.17.2
$I(\NVar{a},\NVar{b},\NVar{x})=I_{x}\left(a,b\right)$
notation used by Magnus et al. (1966); §8.1
$\mathrm{idem}\left(\NVar{\chi_{1}};\NVar{\chi_{2},\dots,\chi_{n}}\right)$
$\mathrm{idem}$ function; §17.1
$\mathrm{Ie}_{\NVar{n}}\left(\NVar{z},\NVar{h}\right)$
modified Mathieu function; 28.20.17
$\mathop{\mathrm{i}^{\NVar{n}}\mathrm{erfc}}\left(\NVar{z}\right)$
repeated integrals of the complementary error function; 7.18.2
$\mathrm{in}_{\NVar{n}}(\NVar{z},\NVar{q})=\mathrm{fe}_{n}\left(z,q\right)$
notation used by Campbell (1955); §28.1
$\inf$
greatest lower bound (infimum); Common Notations and Definitions
$\mathrm{inh}_{\NVar{n}}(\NVar{z},\NVar{q})=\mathrm{Fe}_{n}\left(z,q\right)$
notation used by Campbell (1955); §28.1
$\mathrm{inv}$
inversion number; §26.14(i)
$\operatorname{inverf}\NVar{x}$
inverse error function; 7.17.1
$\operatorname{inverfc}\NVar{x}$
inverse complementary error function; 7.17.1
$\mathrm{Io}_{\NVar{n}}\left(\NVar{z},\NVar{h}\right)$
modified Mathieu function; 28.20.18