等值多用于数学、化学、逻辑等精密科学领域，意为一种绝对的对称和平等关系。
Equivalence is mostly used in several scientific fields such as mathematics, chemistry, and logic, indicating absolute equality in relationship.
实质上适当，即所有(t)形等值式是该定义的逻辑后承。
The adequacy condition require that all the equivalence of the form (t) should are logical consequence of this definition.
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