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\node[align=center] (d) at (-6.5,3.666667) {$\mathcal{M}\mathcal{C}\mathcal{F}_2 = \mathcal{H}\mathcal{R}\mathcal{S}_4^{\mathrm{rf}} = \mathcal{H}\mathcal{R}\mathcal{S}_5^{\mathrm{rf}}$\\$= \mathcal{H}\mathcal{R}\mathcal{S}_4 = \mathcal{H}\mathcal{R}\mathcal{S}_5$};
\node[align=center] (h) at (-6.5,5.666667) {$\mathcal{M}\mathcal{C}\mathcal{F}_k = \mathcal{H}\mathcal{R}\mathcal{S}_{2k}^{\mathrm{rf}} = \mathcal{H}\mathcal{R}\mathcal{S}_{2k+1}^{\mathrm{rf}}$\\$= \mathcal{H}\mathcal{R}\mathcal{S}_{2k} = \mathcal{H}\mathcal{R}\mathcal{S}_{2k+1}$};
\node[align=center] (l) at (-6.5,7.666667) {$\mathcal{M}\mathcal{C}\mathcal{F}_{k+1} = \mathcal{H}\mathcal{R}\mathcal{S}_{2k+2}^{\mathrm{rf}} = \mathcal{H}\mathcal{R}\mathcal{S}_{2k+3}^{\mathrm{rf}}$\\$= \mathcal{H}\mathcal{R}\mathcal{S}_{2k+2} = \mathcal{H}\mathcal{R}\mathcal{S}_{2k+3}$};
\node[align=center] (r) at (-6.5,9.666667) {$\mathcal{M}\mathcal{C}\mathcal{F} = \mathcal{H}\mathcal{R}\mathcal{S}^{\mathrm{rf}} = \mathcal{H}\mathcal{R}\mathcal{S}$};
\node[align=center] (c) at (0.0,0.833333) {$\mathcal{C}\mathcal{F} = \mathcal{M}\mathcal{C}\mathcal{F}_1 = \mathcal{H}\mathcal{R}\mathcal{S}_2^{\mathrm{rf}} = \mathcal{H}\mathcal{R}\mathcal{S}_3^{\mathrm{rf}}$\\$= \mathcal{H}\mathcal{R}\mathcal{S}_2 = \mathcal{H}\mathcal{R}\mathcal{S}_3$};
\node[align=center] (e) at (0.0,2.5) {$\mathcal{E}\mathcal{O}\mathcal{L} = \mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2,1}^{\mathrm{rf}}$\\$= \mathcal{W}\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2,1}^{\mathrm{rf}} = \mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2,1}$};
\node[align=center] (f) at (0.0,4.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{3,1}^{\mathrm{rf}}$};
\node[align=center] (i) at (0.0,5.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{4,1}^{\mathrm{rf}}$};
\node[align=center] (j) at (0.0,6.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{5,1}^{\mathrm{rf}}$};
\node[align=center] (m) at (0.0,7.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k,1}^{\mathrm{rf}}$};
\node[align=center] (o) at (0.0,8.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k+1,1}^{\mathrm{rf}}$};
\node[align=center] (y) at (0.0,9.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k+2,1}^{\mathrm{rf}}$};
\node[align=center] (yy) at (0.0,10.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k+3,1}^{\mathrm{rf}}$};
\node[align=center] (s) at (0.0,11.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{\underline{\,\,\,},1}^{\mathrm{rf}}$};
\node[align=center] (v) at (0.0,13.0) {$\mathcal{C}\mathcal{S}$};
\node[align=center] (w) at (0.0,14.0) {$\mathcal{R}\mathcal{E}\mathcal{C}$};
\node[align=center] (g) at (4.0,4.5) {$\mathcal{W}\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{3,1}^{\mathrm{rf}}$};
\node[align=center] (k) at (4.0,5.5) {$\mathcal{W}\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{4,1}^{\mathrm{rf}}$};
\node[align=center] (n) at (4.0,6.5) {$\mathcal{W}\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{5,1}^{\mathrm{rf}}$};
\node[align=center] (p) at (4.0,7.5) {$\mathcal{W}\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k,1}^{\mathrm{rf}}$};
\node[align=center] (q) at (4.0,8.5) {$\mathcal{W}\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k+1,1}^{\mathrm{rf}}$};
\node[align=center] (x) at (4.0,9.5) {$\mathcal{W}\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k+2,1}^{\mathrm{rf}}$};
\node[align=center] (xx) at (4.0,10.5) {$\mathcal{W}\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k+3,1}^{\mathrm{rf}}$};
\node[align=center] (u) at (4.0,11.5) {$\mathcal{W}\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{\underline{\,\,\,},1}^{\mathrm{rf}}$};
\node[align=center] (yg) at (8.0,5.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{3,1}$};
\node[align=center] (yk) at (8.0,6.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{4,1}$};
\node[align=center] (yn) at (8.0,7.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{5,1}$};
\node[align=center] (yp) at (8.0,8.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k,1}$};
\node[align=center] (yq) at (8.0,9.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k+1,1}$};
\node[align=center] (yx) at (8.0,10.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k+2,1}$};
\node[align=center] (yxx) at (8.0,11.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{2k+3,1}$};
\node[align=center] (yu) at (8.0,12.0) {$\mathcal{P}\mathcal{H}\mathcal{R}\mathcal{S}_{\underline{\,\,\,},1}$};
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\end{document}