Mathematical symbol for 'slightly greater than'? I am wondering if there is a mathematical symbol which indicates that a value is slightly greater than, or slightly less than, another value. I know there is a symbol which indicates that a value is much greater than, or much less than, another value:
$$a\gg b \qquad\text{or}\qquad a\ll b$$
I am wondering if there is a counterpart to this, which indicates:
$$a\,\text{ is slightly greater than }\, b \qquad\text{or}\qquad a \,\text{ is slightly less than }\, b$$
 A: More often it is used as $b=a+\epsilon$ where $\epsilon$ normally stands for a small positive quantity. That provides b slightly greater than a. Similarly $-\epsilon$ for slightly below.
A: Perhaps:
$$\lt_\epsilon\quad\gt_\epsilon\quad\lt^\epsilon\quad\gt^\epsilon$$
using the idea that $a\lt^\epsilon b$ means $a+\epsilon=b$, where $\epsilon\gt0$.
A: This could be a comment, but given all the comments under the OP's question, I don't think anyone would notice it. Thus I am posting this as an answer.

I was taught that the symbols for not much less than and not much greater than are $\eqslantless$ and $\eqslantgtr$ ($\eqslantless$ and $\eqslantgtr$) respectively. This notation is a bit old-style, but my teacher said this was what he was taught when younger (which would explain why the notation is, as mentioned before, old-style).
However, it is on a slant, and my teacher did not write it with a slant; instead, he wrote the symbols as $\require{HTML} \style{display: inline-block; transform: rotate(180deg)}{\ge}$ and $\require{HTML} \style{display: inline-block; transform: rotate(180deg)}{\le}$ (each having a very long typeset command). So, $$a\,\text{ is slightly greater than }\, b \qquad\text{or}\qquad a \,\text{ is slightly less than }\, b$$ is equivalent to $$a\space\,\require{HTML} \style{display: inline-block; transform: rotate(180deg)}{\le}b\qquad\text{or}\qquad a\space\,\require{HTML} \style{display: inline-block; transform: rotate(180deg)}{\ge}b.$$ But I definitely prefer @dxiv 's comment mentioning $\gtrsim$ and $\lesssim$.
A: No. There isn't such a symbol.
A: Of course there' s  no  clear boundary between  small,large numbers in mathematics it's possible to describe a given number is slightly greater or less than the other considering very small difference between the two numbers. that is @ infinite Small   label.(i,e. by ε ),then b=a+ε  or b=a-ε. but only for one number it can be expressed as a- for a number near to left and  a+ for a number near to right.
A: I see this question as a bit of fun, so how about this?

EDIT: Here is a more general version that works for both slightly less than and also much less than:

A: Some suggestion really no answer:
Greater but approximately only greater than $ \approx > $ 
and 
Less but approximately only less than $ \approx <. $
A: The "much greater" symbol $\gg$ is not exactly standard and should always come with an explanation. 
There is no standard symbol for "slightly greater". It is the kind of thing best explained in English or made precise mathematically, as suggested by AHusain
A: 0 < (a-b) << b
This depends on your definition of "slightly"
A: Like @Vlad, "I see this question as a bit of fun", so I want to propose something as well.
Since there is no standard notation, this leaves room for creativity. 
A lot of people proposed ideas like $<^\varepsilon$ to emphasize the idea that $x$ is slightly inferior to $y$ means that $x<y$, but $x+\varepsilon$ is not.
I want to see the problem the other way around, and propose
$$x=^{<\varepsilon}y.$$
This emphasizes the idea that "$x=y$", which means $x$ and $y$ are almost equals... but $x$ is still inferior to $y$ by a $\varepsilon$.
