TY - Computer Science A1 - LI Su-ting,ZHANG Yan T1 - Axiomatizing Covariation-Contravariation Simulation Under GSOS Operators Y1 - 2020-01-15 JF - Computer Science JO - Computer Science SP - 51 EP - 58 VL - 47 IS - 1 UR - https://www.jsjkx.com N1 - 10.11896/jsjkx.181102026 ER -