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+*View this file with results and syntax highlighting [here](https://mlochbaum.github.io/BQN/help/undo.html).*
+
+# Superscript Equals Sign (`⁼`)
+    
+## `𝔽⁼ 𝕩`, `𝕨 𝔽⁼ 𝕩`: Undo
+    
+Invert the function `𝔽`, or use its defined inverse. Not all functions have inverses.
+    
+    
+           1 - 2
+
+           1 -⁼ 2
+
+           √ 16
+
+           √⁼ 4
+
+           ⋆ 1
+
+           ⋆⁼ 2.718281828459045
+
+