Add "Wentzel-Kramers-Brillouin approximation"

1 files changed, 1 insertions, 1 deletions

diff --git a/latex/know/concept/pauli-exclusion-principle/source.md b/latex/know/concept/pauli-exclusion-principle/source.md
index e9e4d42..8870c0c 100644
--- a/latex/know/concept/pauli-exclusion-principle/source.md
+++ b/latex/know/concept/pauli-exclusion-principle/source.md
@@ -87,7 +87,7 @@ $$\begin{aligned}
     \ket{\Psi(a, b)}_f = C \big( \ket{a}\ket{b} - \ket{b}\ket{a} \big)
 \end{aligned}$$
 
-This state called *antisymmetric* under exchange: switching $a$ and $b$
+This state is called *antisymmetric* under exchange: switching $a$ and $b$
 causes a sign change, as we would expect for fermions.
 
 Now, what if the particles $x_1$ and $x_2$ are in the same state $a$?