Muons in EASs with $E_0={10}^{19}$ eV according to data of the Yakutsk Array

Lateral distribution functions of particles in extensive air showers with the energy $E_0\simeq {10}^{19}$ eV recorded by ground-based and underground scintillation detectors with a threshold of $E_{\mu }\simeq 1.0\times \sec \theta$ GeV at the Yakutsk array during the continuous observations from 1986 to 2016 have been analyzed using events with zenith angles $\theta \le {60}^{\circ }$ functions have been compared to the predictions obtained with the QGSJet01 hadron interaction model by applying the CORSIKA code. The entire dataset indicates that cosmic rays consist predominantly of protons.