*Definition [#mdf1808d]
-A topological space (X,τ) is R_{YS} iff for x,y in X, &ref(http://www.eaflux.com/imgtex/imgtex.fcgi?%5bres=100%5d%7b%5c%5b%20%5coverline%7b%5c%7bx%5c%7d%7d%5cneq%5coverline%7b%5c%7by%5c%7d%7d%20%5c%5d%7d%25.png); implies &ref(http://www.eaflux.com/imgtex/imgtex.fcgi?%5bres=100%5d%7b%5c%5b%20%5coverline%7b%5c%7bx%5c%7d%7d%5ccap%5coverline%7b%5c%7by%5c%7d%7d=%5cemptyset%2c%5c%20%5c%7bx%5c%7d%5cmbox%7b%20or%20%7d%5c%7by%5c%7d%20%5c%5d%7d%25.png);.


*Property [#mff90fa5]
-R_{YS} ⇒ [[R_Y]].
-R_{YS} + [[T_0]] = [[T_{YS}]].

*Reference [#l8b853ae]
+Misra, D. N.; Dube, K. K., ''Some axioms weaker than the R0-axiom.'', (Serbo-Croatian summary), Glasnik Mat. Ser. III 8(28) (1973), 145–148. 
+Tong, Jing Cheng, ''On the separation axiom R0.'' (Serbo-Croatian summary), Glas. Mat. Ser. III 18(38) (1983), no. 1, 149–152.