[Home](./index.md) > [kibana-plugin-plugins-expressions-public](./kibana-plugin-plugins-expressions-public.md) > [ExpressionFunctionDefinitions](./kibana-plugin-plugins-expressions-public.expressionfunctiondefinitions.md) ## ExpressionFunctionDefinitions interface A mapping of `ExpressionFunctionDefinition`s for functions which the Expressions services provides out-of-the-box. Any new functions registered by the Expressions plugin should have their types added here. Signature: ```typescript export interface ExpressionFunctionDefinitions ``` ## Properties | Property | Type | Description | | --- | --- | --- | | [clog](./kibana-plugin-plugins-expressions-public.expressionfunctiondefinitions.clog.md) | ExpressionFunctionClog | | | [cumulative\_sum](./kibana-plugin-plugins-expressions-public.expressionfunctiondefinitions.cumulative_sum.md) | ExpressionFunctionCumulativeSum | | | [derivative](./kibana-plugin-plugins-expressions-public.expressionfunctiondefinitions.derivative.md) | ExpressionFunctionDerivative | | | [font](./kibana-plugin-plugins-expressions-public.expressionfunctiondefinitions.font.md) | ExpressionFunctionFont | | | [moving\_average](./kibana-plugin-plugins-expressions-public.expressionfunctiondefinitions.moving_average.md) | ExpressionFunctionMovingAverage | | | [theme](./kibana-plugin-plugins-expressions-public.expressionfunctiondefinitions.theme.md) | ExpressionFunctionTheme | | | [var\_set](./kibana-plugin-plugins-expressions-public.expressionfunctiondefinitions.var_set.md) | ExpressionFunctionVarSet | | | [var](./kibana-plugin-plugins-expressions-public.expressionfunctiondefinitions.var.md) | ExpressionFunctionVar | |