let il be Element of NAT ; :: thesis: NIC (halt SCM+FSA ),il = {il}
now
let x be set ; :: thesis: ( x in {il} iff x in { (IC (Following (ProgramPart s),s)) where s is Element of product the Object-Kind of SCM+FSA : ( IC s = il & (ProgramPart s) /. il = halt SCM+FSA ) } )
A1: now
reconsider il1 = il as Element of ObjectKind (IC SCM+FSA ) by AMI_1:def 11;
reconsider I = halt SCM+FSA as Element of the Object-Kind of SCM+FSA . il by AMI_1:def 14;
reconsider n = il1 as Element of NAT ;
consider t being State of SCM+FSA ;
assume A2: x = il ; :: thesis: x in { (IC (Following (ProgramPart s),s)) where s is Element of product the Object-Kind of SCM+FSA : ( IC s = il & (ProgramPart s) /. il = halt SCM+FSA ) }
reconsider p = (IC SCM+FSA ),il --> il1,I as PartState of SCM+FSA by AMI_1:149;
reconsider u = t +* p as Element of product the Object-Kind of SCM+FSA by PBOOLE:155;
A3: IC u = n by AMI_1:129;
dom ((IC SCM+FSA ),il --> il1,I) = {(IC SCM+FSA ),il} by FUNCT_4:65;
then A4: IC SCM+FSA in dom ((IC SCM+FSA ),il --> il1,I) by TARSKI:def 2;
X: (ProgramPart u) /. il = u . il by AMI_1:150;
A5: u . n = halt SCM+FSA by AMI_1:129;
then IC (Following (ProgramPart u),u) = u . (IC SCM+FSA ) by A3, AMI_1:def 8, X
.= ((IC SCM+FSA ),il --> il1,I) . (IC SCM+FSA ) by A4, FUNCT_4:14
.= il by AMI_1:48, FUNCT_4:66 ;
hence x in { (IC (Following (ProgramPart s),s)) where s is Element of product the Object-Kind of SCM+FSA : ( IC s = il & (ProgramPart s) /. il = halt SCM+FSA ) } by A2, A5, A3, X; :: thesis: verum
end;
now
assume x in { (IC (Following (ProgramPart s),s)) where s is Element of product the Object-Kind of SCM+FSA : ( IC s = il & (ProgramPart s) /. il = halt SCM+FSA ) } ; :: thesis: x = il
then ex s being Element of product the Object-Kind of SCM+FSA st
( x = IC (Following (ProgramPart s),s) & IC s = il & (ProgramPart s) /. il = halt SCM+FSA ) ;
hence x = il by AMI_1:def 8; :: thesis: verum
end;
hence ( x in {il} iff x in { (IC (Following (ProgramPart s),s)) where s is Element of product the Object-Kind of SCM+FSA : ( IC s = il & (ProgramPart s) /. il = halt SCM+FSA ) } ) by A1, TARSKI:def 1; :: thesis: verum
end;
hence NIC (halt SCM+FSA ),il = {il} by TARSKI:2; :: thesis: verum