\begin{tikzpicture}[node distance=1cm]
    % ノードの定義
    \node[draw, rectangle, minimum width=13cm, minimum height=2cm, align=left, font=\Large] (A) at (0, 0) {
        PAC Causal Identification via Model Checking (Algorithm \ref{Alg_PG_SPREst}) \\
        1) Compute $\mathcal{S}_{N, \delta, \beta}$ and $\{ C^*_{S_N, u} \}_{u \in \mathcal{U}_N}$ defined as (\ref{S_delta_beta}) and (\ref{canonical_cause}).\\
        2) Compute $\mathcal{C}^*$ defined as (\ref{C_star}). \textbf{( Solution )}
    };

    \node[draw=none, align=left, font=\Large] (E) at (-5, 5) {
        1) Distribution $\mathbb{P}$ over $\mathcal{V}$\\
        2) Sample size $N$
    };

    \node[draw, rectangle, minimum width=3cm, minimum height=1.5cm, align=center, font=\Large] (B) at (-5, 3) {Sample\\ parameters};
    \node[draw, rectangle, line width=0.7mm, minimum width=4cm, minimum height=1.5cm, align=center, font=\Large] (C) at (0, 3) {Theorems 1 and 2:\\ Compute $\eta_N$ and $\zeta_N$};
    \node[draw, rectangle, line width=0.7mm, minimum width=3cm, minimum height=1.5cm, align=center, font=\Large] (D) at (5.0, 3.2) {Theorem 3:\\ Guarantee\\ \textbf{(PC1)} and \textbf{(PC2)}};

    \node[draw=none] (Empty) at (-3, 4.2) {};
    \node[draw=none, align=left, font=\Large] (F) at (-1.1, 4.4) {
        pMDP $\mathcal{M}_u$, $\delta$, and $\beta$
    };

    \node[draw=none, align=left, font=\Large] (G) at (2.0, 1.5) {
        $\mathcal{C}^*$ and $\mathcal{S}_{N, \delta, \beta}$
    };

    \node[draw=none, align=left, font=\Large] (H) at (-4.5, 1.5) {
        $\mathcal{U}_N$
    };

    % 矢印の定義
    \draw[->, >=stealth, thick] (E) -- (B);
    \draw[->, >=stealth, thick] (B.south) -- ++(0, -1.1) -- (A);
    \draw[->, >=stealth, thick] (A) -- ++(0, 2) coordinate (mid) -- (C);
    \draw[->, >=stealth, thick] (mid) -| (D);

    \draw[->, >=stealth, thick] (Empty.south) -- ++(0,-2) -- (A);

\end{tikzpicture}