Commutative law teaching designs addition significance and addition .
加法的意义和加法交换律教学设计。
To satisfy or engage in a commutative operation .
直接转换符合或从事交换操作。
Unlike classical groups , which act on commutative spaces , quantum groups act on nocommutative spaces ( e.g. where xy doesn 't equal yx ) , which emerges through their unique curvature and quantum uncertainty .
