∀)"/> ∀)"/> ∀)"/> The compose key and ~/.XCompose | Gavide's Blog
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Toggle Navigation Home<br>blog<br>compose-key-linux<br>The compose key and ~/.XCompose<br>May 29, 2026 Motivation<br>I have recently been looking for ways to type math symbols effortlessly without having to look them up and copy and paste them, such as ∀∃∪∩⇒∈[…].<br>As an Italian with a US keyboard layout, I had also wondered for some time how to type ‘è’ (and similar letters) without constantly switching layouts.<br>After some trial and error, I found a solution that works decently (it’s not perfect, see below1): the ~/.XCompose configuration file (https://wiki.debian.org/XCompose).<br>In the examples below, is the compose key, represented as in ~/.XCompose. It is necessary to set up the key binding on your system first. It is easy to do on KDE. I chose the key in my setup.<br>This is my ~/.XCompose configuration. It allows me to type \ a l l, which inserts the character ”∀“.<br>For Flatpak apps, allow them to read the ~/.XCompose file1:<br>flatpak override --user --filesystem=~/.XCompose ~/.XCompose<br>include "%L"
Multi_key> backslash> c> u> p> : "∪" U222A<br>Multi_key> backslash> c> a> p> : "∩" U2229
# : "∀" U2200<br>Multi_key> backslash> f> o> r> : "∀" U2200<br>Multi_key> backslash> a> l> l> : "∀" U2200<br># : "∃" U2203<br>Multi_key> backslash> e> x> : "∃" U2203<br>Multi_key> backslash> i> n> : "∈" U220A<br>Multi_key> backslash> n> o> t> i> n> : "∉" U2209<br>Multi_key> backslash> s> u> b> s> e> t> : "⊂" U2282<br>Multi_key> backslash> s> u> p> s> e> t> : "⊃" U2283<br>Multi_key> backslash> e> m> p> t> y> s> e> t> : "∅" U2205
Multi_key> backslash> a> n> d> : "∧" U2227<br>Multi_key> backslash> o> r> : "∨" U2228<br>Multi_key> backslash> n> o> t> : "¬" U00AC<br>Multi_key> backslash> t> o> : "→" U2192<br>Multi_key> backslash> i> m> p> l> i> e> s> : "⇒" U21D2<br>Multi_key> backslash> i> f> f> : "⇔" U21D4
# Conflicts with in<br># : "∫" U222B<br>Multi_key> backslash> s> u> m> : "∑" U2211<br>Multi_key> backslash> p> r> o> d> : "∏" U220F<br># : "∞" U221E<br>Multi_key> backslash> n> a> b> l> a> : "∇" U2207<br>Multi_key> backslash> p> a> r> t> i> a> l> : "∂" U2202
Multi_key> backslash> p> m> : "±" U00B1<br>Multi_key> backslash> m> p> : "∓" U2213<br>Multi_key> backslash> t> i> m> e> s> : "×" U00D7<br>Multi_key> backslash> d> i> v> : "÷" U00F7<br>Multi_key> backslash> c> d> o> t> : "⋅" U22C5
Multi_key> backslash> n> e> q> : "≠" U2260<br>Multi_key> backslash> l> e> q> : "≤" U2264<br>Multi_key> backslash> g> e> q> : "≥" U2265<br>Multi_key> backslash> a> p> p> r> o> x> : "≈" U2248<br>Multi_key> backslash> e> q> u> i> v> : "≡" U2261<br>Multi_key> backslash> p> r> o> p> o> r> t> i> o> n> a> l> : "∝" U221D
Multi_key> backslash> a> l> p> h> a> : "α" U03B1<br>Multi_key> backslash> b> e> t> a> : "β" U03B2<br>Multi_key> backslash> g> a> m> m> a> : "γ" U03B3<br>Multi_key> backslash> d> e> l> t> a> : "δ" U03B4<br>Multi_key> backslash> p> i> : "π" U03C0<br>Multi_key> backslash> t> h> e> t> a> : "θ" U03B8<br>Multi_key> backslash> l> a> m> b> d> a> : "λ" U03BB<br>Multi_key> backslash> m> u> : "μ" U03BC<br>Multi_key> backslash> D> e> l> t> a> : "Δ" U0394<br>On some Flatpak apps under Wayland, the custom key bindings are not detected. I remember finding a hacky workaround, probably running the Flatpak apps with XWayland, but it led to some issues and I backtracked.<br>Apps like Google Chrome try to hijack the compose key and implement their own version of it, which also does not use this configuration.↩
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