less-than sign

The less-than sign, {{char|<}}, is an original ASCII character (hex 3C, decimal 60).

In BASIC, Lisp-family languages, and C-family languages (including Java and C++), comparison operator < means "less than".

In Coldfusion, operator .lt. means "less than".

In Fortran, operator .LT. means "less than"; later versions allow <.

In Bourne shell (and many other shells), operator -lt means "less than". Less-than sign is used to redirect input from a file. Less-than plus ampersand ({{code|<&}}) is used to redirect from a file descriptor.

The double less-than sign, {{char|<<}}, may be used for an approximation of the much-less-than sign ({{char|≪}}) or of the opening guillemet ({{char|«}}). ASCII does not encode either of these signs, though they are both included in Unicode.

In Bash, Perl, and Ruby, operator {{code|<here document.

In C and C++, operator {{code|<<}} represents a binary left shift.

In the C++ Standard Library, operator {{code|<<}}, when applied on an output stream, acts as insertion operator and performs an output operation on the stream.

In Ruby, operator {{code|<<}} acts as append operator when used between an array and the value to be appended.

In XPath the {{code|<<}} operator returns true if the left operand precedes the right operand in document order; otherwise it returns false.{{cite web |date=14 December 2010 |title=XML Path Language (XPath) 2.0 (Second Edition) |url=https://www.w3.org/TR/xpath20/#id-node-comparisons |archive-url=https://web.archive.org/web/20221007124416/https://www.w3.org/TR/xpath20/#id-node-comparisons |archive-date=7 October 2022 |access-date=29 October 2019 |website=www.w3.org |publisher=W3C}}

In PHP, operator {{code|<<heredoc statement (where OUTPUT is an arbitrary named variable.)

In Bash, {{code|<<

The less-than sign with the equals sign, {{code|1=<=}}, may be used for an approximation of the less-than-or-equal-to sign, {{char|≤}}. ASCII does not have a less-than-or-equal-to sign, but Unicode defines it at code point U+2264.

In BASIC, Lisp-family languages, and C-family languages (including Java and C++), operator {{code|1=<=}} means "less than or equal to". In Sinclair BASIC it is encoded as a single-byte code point token.

In Prolog, {{code|1==<}} means "less than or equal to" (as distinct from the arrow {{code|1=<=}}).

In Fortran, operators {{code|.LE.}} and {{code|1=<=}} both mean "less than or equal to".

In Bourne shell and Windows PowerShell, the operator {{code|-le}} means "less than or equal to".

In the R programming language, the less-than sign is used in conjunction with a hyphen-minus to create an arrow ({{code|<-}}), this can be used as the left assignment operator.

The less-than sign is used in the spaceship operator.

In HTML (and SGML and XML), the less-than sign is used at the beginning of tags. The less-than sign may be included with <. The less-than-or-equal-to sign, {{char|≤}}, may be included with ≤.

Unicode provides various less than symbols:{{Cite web |title=Less than symbol |url=https://lessthansymbol.com/ |access-date=2023-06-06 |archive-date=2023-05-16 |archive-url=https://web.archive.org/web/20230516200208/https://lessthansymbol.com/ |url-status=live }}

The less-than sign may be seen for an approximation of the opening angle bracket, {{char|⟨}}. True angle bracket characters, as required in linguistics notation, are expected in formal texts.

==Mathematics==

In an inequality, the less-than sign and greater-than sign always "point" to the smaller number. Put another way, the "jaws" (the wider section of the symbol) always direct to the larger number.

The less-than-sign is sometimes used to represent a total order, partial order or preorder. However, the symbol {{char|$\backslash prec$}} is often used when it would be confusing or not convenient to use {{char|<}}. In mathematical writing using LaTeX, the TeX command is {{code|\prec }}. The Unicode code point is {{nobr|{{unichar|227A}}}}.

• Inequality (mathematics)
• Greater-than sign
• Relational operator
• Much-less-than sign

{{Reflist}}

Category:Typographical symbols

Category:Mathematical symbols

Category:Inequalities (mathematics)