if and only if meaning in English
逻辑双条件
若且唯若当且仅当
若且为若
实质等价
双条件
Examples
- Positive semi-definite matrices are positive definite if and only if they are nonsingular .
正半定矩阵是正定的，当且仅当它们是非奇异矩阵。 - Two sets are said to be equivalent if and only if they can be placed in one-to-one correspondence .
当且仅当两个集合中的元素一一对应时，才称它们为等势。 - Theorem 1 and are equivalent infinitesimals if and only if
定理1与是等阶无穷小的充分必要条件为 - A node - set is true if and only if it is non - empty
一个节点当且仅当它不是空节点时，表达式的值为真。 - Specifies the block of code to execute if and only if the conditions of all
元素的条件的计算结果均为