WORST_CASE(?,O(n^1))
* Step 1: NaturalPI WORST_CASE(?,O(n^1))
    + Considered Problem:
        - Strict TRS:
            =(.(x,y),.(u(),v())) -> and(=(x,u()),=(y,v()))
            =(.(x,y),nil()) -> false()
            =(nil(),.(y,z)) -> false()
            =(nil(),nil()) -> true()
            del(.(x,.(y,z))) -> f(=(x,y),x,y,z)
            f(false(),x,y,z) -> .(x,del(.(y,z)))
            f(true(),x,y,z) -> del(.(y,z))
        - Signature:
            {=/2,del/1,f/4} / {./2,and/2,false/0,nil/0,true/0,u/0,v/0}
        - Obligation:
            innermost runtime complexity wrt. defined symbols {=,del,f} and constructors {.,and,false,nil,true,u,v}
    + Applied Processor:
        NaturalPI {shape = Linear, restrict = NoRestrict, uargs = UArgs, urules = URules, selector = Nothing}
    + Details:
        We apply a polynomial interpretation of kind constructor-based(linear):
        The following argument positions are considered usable:
          uargs(.) = {2},
          uargs(f) = {1}
        
        Following symbols are considered usable:
          {=,del,f}
        TcT has computed the following interpretation:
              p(.) = 1 + x1 + x2                
              p(=) = 12 + 4*x1                  
            p(and) = 4                          
            p(del) = 13*x1                      
              p(f) = 2*x1 + 2*x2 + 13*x3 + 13*x4
          p(false) = 9                          
            p(nil) = 2                          
           p(true) = 12                         
              p(u) = 0                          
              p(v) = 0                          
        
        Following rules are strictly oriented:
        =(.(x,y),.(u(),v())) = 16 + 4*x + 4*y         
                             > 4                      
                             = and(=(x,u()),=(y,v())) 
        
             =(.(x,y),nil()) = 16 + 4*x + 4*y         
                             > 9                      
                             = false()                
        
             =(nil(),.(y,z)) = 20                     
                             > 9                      
                             = false()                
        
              =(nil(),nil()) = 20                     
                             > 12                     
                             = true()                 
        
            del(.(x,.(y,z))) = 26 + 13*x + 13*y + 13*z
                             > 24 + 10*x + 13*y + 13*z
                             = f(=(x,y),x,y,z)        
        
            f(false(),x,y,z) = 18 + 2*x + 13*y + 13*z 
                             > 14 + x + 13*y + 13*z   
                             = .(x,del(.(y,z)))       
        
             f(true(),x,y,z) = 24 + 2*x + 13*y + 13*z 
                             > 13 + 13*y + 13*z       
                             = del(.(y,z))            
        
        
        Following rules are (at-least) weakly oriented:
        

WORST_CASE(?,O(n^1))