The phrase "already exist for this" is correct and usable in written English.
It can be used when discussing whether something is currently available or in existence for a particular purpose or context.
Example: "Before we proceed with the new project, we should check if any resources already exist for this initiative."
Alternatives: "are already available for this" or "currently exist for this".
First, we are not trying to reinvent the wheel, but leverage instead captive channels and customer touchpoints that already exist for this category (e.g. price comparison websites, property sites etc); given how relevant the category is, we are quite lucky that a lot of low cost digital touchpoints exist, and that customers comfort of navigating these has been built in the last few years.
A number of systems already exist for this purpose (Tanaka et al., 2001, 2003, 2005), but since these systems are designed based on NIM (U.S. NIM Committee, 1990) and CAMAC (IEEE, 1982) system, power consumption is large and the systems require commercial power supplies.
A number of software packages already exist for this purpose (Supplementary Table 1).
However, many optimizations already exist for this algorithm, partitioning or sampling the data in such a way that they do fit in memory.
Several programs, imaging libraries and internet resources already exist for this purpose, however, most are either limited in the number of comparisons they can show, are unable to adequately utilise draft genome sequence data, or require a knowledge of command-line scripting for implementation.
Recent scholarship on servitude law clearly indicates that such a background theory already exists for this restatement.
The White House College Scorecard already exists for this purpose, though its utility to consumers is debatable.
With creative use of funding that already exists for this population, "job coaches" can be provided to act as moral and physical supports to workers with special needs.
