Shell Environment

[lostinplace]

Construct a runtime environment that accepts the following commands:

Command	Effect
{rule}	Add Rule to current engine
.	increments the state of the engine, then prints the active references
+{name}	activates the named reference
+{name} = {value}	activates the named reference with the provided value
explore {n}	conducts an exploration of n iterations and prints the distribution of outcomes
?	prints the current engine context
?{name}	prints the state of the named reference
quit	exits the environment
help	shows the list of commands