Referencing Non-Equations ("See Eq. (15)/See Ineq. (15)") When I write something like

x is a stochastic function of y:
    x ~ N(2y, 3)                      (1),


how do I refer back to that... non-equation?  Do I still put "see Eq. (1)" although (1) is not an equation?
It seems that the right thing to do will depend on what's conventional in your field.  In pure mathematics, it's standard to refer to all displayed equations, inequalities, etc. using just numbers in parentheses (for example, "using (2.1)", without specifying there whether (2.1) is an equation).  You could add a descriptive noun if you'd like to emphasize it (e.g., "using equation (2.1)"), but you don't need to.  If you do add a noun, it could be considered strange to refer to anything but an actual equation as an equation.  This style of referencing displays creates no ambiguity, since citations use square brackets and all other numerical references have an attached noun or symbol to indicate whether they refer to a theorem, section, etc.: [1] is a citation, (1) is an equation or other display, Lemma 1 is a lemma, Section 1 is a section, etc.

The system described in the previous paragraph presumably doesn't apply to the author of the question, since abbreviations like "Eq. (1)" or "Ineq. (1)" are not standard in pure mathematics, which suggests he is in another field.  However, it's worth keeping in mind that conventions vary between fields, so there won't be an absolute answer to this question.  To know for sure what would look reasonable, it's important to know the context (i.e., the audience for the paper and where it might be published).