The phrase "a straightforward rule" is correct and usable in written English.
You can use it when referring to a simple and clear guideline or principle that is easy to understand and follow.
Example: "In our organization, we have a straightforward rule: always communicate openly and honestly with your team members."
Alternatives: "a simple guideline" or "an easy principle".
Problem (1// - overline{al}) gives rise to a very straightforward rule for finding the optimal schedule, namely the most profit ratio first (MPRF) rule.
I'd say that's a fairly straightforward rule to live by.
Probably the most important result about first-order languages is the Gödel completeness theorem which of course says that the set of all valid formulas of any first-order language L can be generated from a simple set of axioms by means of a few straightforward rules of inference.
This large sample from the relatively small population of Iceland allowed them to implement the long-range phasing with a fairly straightforward rule-based method which does not take full use of the data but disregards partly inconsistent information [Hickey et al., 2011; Kong et al., 2008].
Yes, more off-putting terms for what is a straightforward enough rule: be consistent.
Bank lobbyists have aggressively lobbied regulators against implementing a straightforward Volcker Rule banning proprietary trading, arguing that would punish harmless trades made on behalf of clients -- so-called market making activities -- or efforts to hedge against risk.
In this paper, a simple shaping design procedure is presented together with straightforward rules to obtain optimal feedforward controllers for the case when the ideal compensator is not realizable due to right-half plane zeros in the process dynamics.
All over one of the most straightforward rules in tennis.
Ms. Yellen said the new regulatory system should incorporate automatic safeguards and straightforward rules, and involve extensive international coordination.
A-life researchers, in conjunction with biologists, have been able to show that such behaviour can and does arise "from the bottom up" by combining remarkably straightforward rules.
