Expand knowledge base

1 files changed, 2 insertions, 1 deletions

diff --git a/content/know/concept/interaction-picture/index.pdc b/content/know/concept/interaction-picture/index.pdc
index 45950ff..89aff58 100644
--- a/content/know/concept/interaction-picture/index.pdc
+++ b/content/know/concept/interaction-picture/index.pdc
@@ -197,7 +197,8 @@ $$\begin{aligned}
     \mathcal{T} \bigg\{ \bigg( \int_{t_0}^{t} \hat{H}_{1,I}(t') \dd{t'} \bigg)^n \bigg\}
 \end{aligned}$$
 
-Here, we recognize the Taylor expansion of $\exp$,
+This construction is occasionally called the **Dyson series**.
+We recognize the well-known Taylor expansion of $\exp\!(x)$,
 leading us to a final expression for $\hat{K}_I$:
 
 $$\begin{aligned}