The therefore sign “” is used especially in handwritten mathematical text as a shorthand of the or relations:
It expresses that has been inferred from or from and some preceding facts. The sign is rather a punctuation mark than a symbol of logical implication. Grammatically, it could be characterised a conclusive coordinating . The usage of the symbol is not mathematically well-defined, and it often means ‘we can conclude in context’ or ‘we can conclude from statements already shown or assumed to be true’.
For example, in determining an angle of a right triangle, one may write
Here, “” does not a proper implication “”, since the exact implication here would be
To obtain a strict implication, we would need to introduce some of the context. For instance, we know that, since is an angle of a right triangle, , so what we wrote could be interpreted as the implication
|Date of creation||2013-03-22 17:55:51|
|Last modified on||2013-03-22 17:55:51|
|Last modified by||pahio (2872)|