The phrase "a subtle relation" is correct and usable in written English.
It can be used to describe a nuanced or delicate connection between two or more concepts, ideas, or entities.
Example: "The study revealed a subtle relation between diet and mental health that had not been previously explored."
Alternatives: "a nuanced connection" or "a delicate link".
Between these terms a more subtle relation exists, that is neither an identity or an opposition: the formal processes of planning supply precise rules and directions for structuring the territory, while informal ones model, occupy and generate space following principles like spontaneity and self-organisation.
This has something importantly to do with religion in American life, and the subtle relation that is posited between conservative Christianity and modern capitalism.
Since previous studies have investigated only general aspects of motor action such as the effectors or direction of motion [10], we report neural markers of the motor-language relation at a subtle aspect of the action (hand-shape).
Khamenei is not known for a subtle mastery of international public relations, but the supreme leader's public reply Thursday had surprising resonance globally, particularly among America's European allies.
In the century that separates us from the futurists, a subtle change has come over the relation of art and technology: if the "avant-garde" (a military term first used with reference to culture and society around 1820 by the French socialist writer Saint-Simon) was once prophetic, it now occupies a subaltern position.
§2 of Van Evra 1997 nicely explores a subtle but important difference in the relation between mathematics and logic in Boole and Peirce.
There is nothing inherently wrong with the service, but it is interesting to note how this kind of public relations can be a subtle kind of payback for favors gained.
During his numerous visits there he perfected a subtle diplomacy that, almost invisibly, transformed British-French relations from animosity to friendship.
