I know the meaning of **tend** and **there is** but I cannot get exact meaning and grammatical rule of **there does tend to be** in the following sentence:

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> In applied mathematics (mechanics, statistics, decision mathematics, and so on), **there does tend to be** more focus on solving problems and less on developing abstract theories. (source: *How to Study for a Mathematics Degree* by Lara Alcock)
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-----Edit (clarifying my question)

What is the difference between the following forms in meaning and what are the grammatical structure of the sentences?

1. **There is** more focus on solving problems.
2. **There tends to be** more focus on solving problems.
3. **There does tend to be** more focus on solving problems.