The phrase "an exact one" is grammatically correct and commonly used in written English.
It can be used to describe a specific and precise thing or person, as opposed to a general or approximate one. Example: "I need you to find me an exact one - not just any red dress, but the exact shade and style I saw in the magazine."
She said the police-spotting feature allowed users to place an icon on a map that gave a rough location -- not an exact one -- and that it didn't enable users to "track" police.
Creating a successful social campaign is a science, although not an exact one as it requires experimentation.
Economics, this seems to say, is not a social science but an exact one, like physics or chemistry – a distinction that not only encourages hubris among economists but also changes the way we think about the economy.
The relationship between skills and economic success is not an exact one, yet it is certainly strong enough to notice, and not just in the reams of peer-reviewed studies on the subject.
Besides, it usually consists of less attributes than an exact one.
On the other hand, a traditional smooth penalty function like the quadratic penalty function cannot be an exact one.
We prove the existence of an exact one-dimensional representation of the three-dimensional theory of linear elasticity for a structural member with constant, two-fold symmetric cross-section, without the use of any a priori assumptions.
After establishing the existence of an exact one-way equation for systems whose coefficients do not vary along the axis of integration, efficient approximations of the one-way operator are constructed by generalizing techniques previously used to create nonreflecting boundary conditions.
Of course, the drone/3D printing comparison isn't an exact one-to-one.
The conclusion is that the extension of the two-step approach to a homogeneous medium investigated with a bistatic radar is possible, and the algorithm is totally equivalent to an exact one-step 3D migration.
However, it also steps rightly by not being an exact one-to-one match with the Sturgess version character-wise, which in turn allows the fun of predicting who will and won't make it to the "ride off into the sunset" shot before the credits.
