Sample dialogs:

C:\logicagent>ruby logicagent.rb
I have loaded C:/logicagent/logicagent-api.yaml.

> All metals are solid.
Okay, All metals are solid.

> Mercury is a metal.
Okay, Mercury is a metal.

> a metal is all metals
Okay, a metal is all metals.

> is Mercury solid?
Yes, Mercury is solid.

> why is Mercury solid?
Mercury is solid because: mercury is a metal, and a metal is all metals, and all metals are solid

> Mercury is not solid.
That contradicts the information I have that Mercury is solid because: 
 mercury is a metal, and a metal is all metals, and all metals are solid.

> forget "all metals are solid."
Okay I have forgotten all metals are solid.

> is Mercury solid?
I have no knowledge that Mercury is solid.

---

The "is" relation is transitive. The graph can store other relations, 
such as "=" which is reflexive, symmetric, and transitive:
---

> reset graph
Okay, I have reset the graph.

> a = b
Okay, a = b.

> does a = a?
Yes, a = a.

> does a = b?
Yes, a = b.

> does b = a?
Yes, b = a.

> b = c
Okay, b = c.

> does a = c?
Yes, a = c.

> print graph
a = b
a = a
b = a
b = b
b = c
c = b
c = c

---

The graph can also store multiple edges (or relations):
---

> All birds have wings.
Okay, All birds have wings.

> All ostriches are birds.
Okay, All ostriches are birds.

> birds are all birds
Okay, birds are all birds.

> do all ostriches have wings?
Yes, all ostriches have wings

> why do all ostriches have wings?
all ostriches have wings because: all ostriches are birds, and birds are all birds, and all birds have wings

---
robertscottmitchell@yahoo.com