\documentclass[border=1pt]{standalone}
\usepackage[polish]{babel}
\usepackage[utf8]{inputenc} 
\usepackage[T1]{fontenc}
\usepackage{fourier}
\usepackage{tikz}
\usetikzlibrary{arrows.meta}

\begin{document}

\begin{tikzpicture}
\node[draw,circle,minimum size=1cm,
  label=above left:$a+2b$, label=below left:$A$] (p2) at (0,0) {p2};
\node[draw,circle,minimum size=1cm,
  label=above left:$2c+2d$, label=below left:$B$] (p1) at (0,2) {p1};
\node[draw,circle,minimum size=1cm,
  label=below right:$A$] (p3) at (6,1) {p3};
\node[draw,minimum width=1.4cm,minimum height=6mm,
  label={below:$[x\ne y]$}] (t) at (3,1) {t};

\draw[-Stealth] (p1) -- node[above] {$x$} (t);
\draw[-Stealth] (p2) -- node[below] {$y$} (t);
\draw[-Stealth] (t) -- node[above] {$2y$} (p3);
\end{tikzpicture}

\end{document}