\[\left\langle\mathscr{F}\left(1\right),\phi\right\rangle=\sqrt{2\pi}\left%
\langle\mathscr{F}\left(\mathscr{F}\left(\delta\right)\right),\phi\right%
\rangle=\sqrt{2\pi}\left\langle\mathscr{F}\left(\delta\right),\mathscr{F}(\phi%
)\right\rangle=\sqrt{2\pi}\left\langle\delta,\mathscr{F}(\mathscr{F}(\phi))%
\right\rangle=\sqrt{2\pi}\left\langle\delta,\phi_{-}\right\rangle=\sqrt{2\pi}%
\phi(0),\]