On the injectivity of the Vassiliev homomorphism of singular Artin monoids

I prove general combinatorial properties which apply to singular Artin monoids and examine their relationship with the Vassiliev homomorphism eta. I show that eta preserves the Intermediate Property, discovered by Corran, which holds in positive singular Artin monoids of finite type. From this it follows that eta is injective for a class of monoids which include singular Artin monoids of type I-2(p), generalising a result of East.