The Mathematical Symbol "Square Image Of (⊏)"

The "Square Image Of" (⊏)

The ⊏ symbol, commonly known as "Square Image Of", is a mathematical notation used to denote a specific type of relationship between sets. Specifically, it's used to indicate that one set is an image of another under a function when dealing with certain mathematical contexts, especially within set theory and related areas.

Understanding the Symbol

The ⊏ symbol represents the notion that one set, say A, is an image of another set, B, under a specific function f. This means that every element of A has an image in B when mapped by the function f. The "square" nature of the symbol often emphasizes a specific kind of function or relation being considered.


The exact usage of ⊏ can depend on the mathematical context. In general, it's used to describe relationships between sets under certain functions or transformations. Its main utility is in abstract mathematical discussions where clarity and specificity of notation are paramount.


If we have a function \( f: A \to B \) and using the ⊏ notation, we might say:

\( A ⊏ B \) under \( f \)

This would indicate that set A is an image of set B under the function \( f \).

Typing ⊏

In digital documents or web content, using the ⊏ entity will render the "Square Image Of" symbol. If working with specialized mathematical software or notation systems, other methods might be employed to display or input this symbol.

Related Symbols

Other related symbols include ⊏ (Square Subset Of) and ⊑ (Square Subset of or Equal To). Each of these symbols provides specific information about the relationship between sets in a given mathematical context.


The ⊏ symbol is a testament to the richness of mathematical notation, offering precision and clarity in describing relationships between sets. Its utility, especially in higher mathematics, helps scholars convey complex ideas effectively and succinctly.

Mathematical symbol 'Square Image Of'

Are You Good at Mathematical Symbols?

Do you know, or can you guess, the technical symbols? Well, let's see!
gold cup

gold cup

gold cup

  • This test has questions.
  • A correct answer is worth 5 points.
  • You can get up to 5 bonus points for a speedy answer.
  • Some questions demand more than one answer. You must get every part right.
  • Beware! Wrong answers score 0 points.
  • 🏆 If you beat one of the top 3 scores, you will be invited to apply for the Hall of Fame.
Scoring System

Guru (+)
Hero (+)
Captain (+)
Sergeant (+)
Recruit (+)

Codes for the ⊏ Symbol

The Symbol
Alt CodeAlt 8847
HTML Code⊏
HTML Entity⊏
CSS Code\228F
Hex Code⊏

How To Insert the ⊏ Symbol

(Method 1) Copy and paste the symbol.

The easiest way to get the ⊏ symbol is to copy and paste it into your document.

Bear in mind that this is a UTF-8 encoded character. It must be encoded as UTF-8 at all stages (copying, replacing, editing, pasting), otherwise it will render as random characters or the dreaded �.

(Method 2) Use the "Alt Code."

If you have a keyboard with a numeric pad, you can use this method. Simply hold down the Alt key and type 8847. When you lift the Alt key, the symbol appears. ("Num Lock" must be on.)

(Method 3) Use the HTML Decimal Code (for webpages).

HTML TextOutput
<b>My symbol: &#8847;</b>My symbol: ⊏

(Method 4) Use the HTML Entity Code (for webpages).

HTML TextOutput
<b>My symbol: &sqsub;</b>My symbol: ⊏

(Method 5) Use the CSS Code (for webpages).

CSS and HTML TextOutput
span:after {
content: "\228F";}
<span>My symbol:</span>
My symbol: ⊏

(Method 6) Use the HTML Hex Code (for webpages and HTML canvas).

HTML TextOutput
<b>My symbol: &#x228F;</b>My symbol: ⊏
On the assumption that you already have your canvas and the context set up, use the Hex code in the format 0x228F to place the ⊏ symbol on your canvas. For example:
JavaScript Text
const x = "0x"+"E9"
ctx.fillText(String.fromCodePoint(x), 5, 5);

(Method 7) Use the Unicode (for various, e.g. Microsoft Office, JavaScript, Perl).

The Unicode for ⊏ is U+228F. The important part is the hexadecimal number after the U+, which is used in various formats. For example, in Microsoft Office applications (e.g. Word, PowerPoint), do the following:
[Hold down Alt]
[Press x]

(The 228F turns into ⊏. Note that you can omit any leading zeros.)
In JavaScript, the syntax is \uXXXX. So, our example would be \u228F. (Note that the format is 4 hexadecimal characters.)
JavaScript TextOutput
let str = "\u228F"
document.write("My symbol: " + str)
My symbol: ⊏