How to use [invoke]

The reference page of invoke has its arguments, constraints and declaration.

This slot works similarly to [eval], except it treats the invocation similarly to an invocation to a dynamic slot, allowing you to pass in arguments, and return nodes from the invocation.

.lambda
   strings.concat
      .:"Hello "
      get-value:x:@.arguments/*/name
   return:x:-
invoke:x:@.lambda
   name:John

Notice, you cannot supply an expression leading to multiple nodes, and the slot invokes the lambda object immutable, such that it doesn’t change. The invocation also does not have access to anything outside of its own lambda object.