Problem

Source: Russian TST 2021, Day 7 P2

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The $A{}$-excircle $\omega_A{}$ of the triangle $ABC$ touches the side of the $BC$ at point $A_1$ and the extensions of the sides $AB$ and $AC$ are at points $C_1$ and $B_1$ respectively. Let $P{}$ be the middle of the segment $B_1C_1$. The line $A_1P$ intersects $\omega_A{}$ a second time at point $X{}$. The tangents to the circumcircle of the triangle $ABC$ at point $A{}$ and to $\omega_A{}$ at point $X{}$ intersect at point $R$. Prove that $RP = RX$.