On sliceness of the knots 6.31445, 6.52373, 6.62002 and 6.86951

In a series of papers H. Boden, M. Chrisman, R. Gaudreau considered the slice status classification of the virtual knots up to six classical crossings. Using Turaev’s graded genus, Rasmussen invariant, generalized Alexander polynomial and extended $\bar\mu$-invariants, they determines sliceness of all but four virtual knots. We finish the classification by giving 75