Binary star is within its Roche lobe, i.e. the area where the gravitational pull of the star itself is larger than that of the other component. The stars have no major effect on each other, and essentially evolve separately. Most binaries belong to this class. "Semidetached binary stars" are binary stars where one of the components fills the binary star's Roche lobe and the other does not. Gas from the surface of the Roche-lobe-filling component (donor) is transferred to the other, accreting star. The mass transfer dominates the evolution of the system. In many cases, the inflowing gas forms an accretion disc
Skew binary number system with formula_8 1s is equal to the binary number formula_9 minus formula_8. Let formula_11 represents the digit formula_12 repeated formula_13 times. The skew binary number of the form formula_14 with formula_8 1s is equal to the binary number formula_16 minus formula_8. Similarly to the preceding section, the binary number formula_18 of the form formula_7 with formula_8 1s equals the skew binary number formula_21 plus formula_8. Note that since addition is not defined, adding formula_8 corresponds to incrementing the number formula_8 times. However, formula_8 is bounded by the logarithm of formula_18 and incrementation takes constant time. Hence transforming a binary number