One actual generated trace

Seed 0 · five ordinary registers + TMP · 8 update assignments · 32 values

01  TMP <- 19;          (None, None, None, None, None, 19)
02  a <- 26;            (26, None, None, None, None, 19)
03  e <- 25;            (26, None, None, None, 25, 19)
04  b <- 2;             (26, 2, None, None, 25, 19)
05  c <- 16;            (26, 2, 16, None, 25, 19)
06  d <- 31;            (26, 2, 16, 31, 25, 19)
07  TMP <- e;           (26, 2, 16, 31, 25, 25)
08  b <- 10;            (26, 10, 16, 31, 25, 25)
09  TMP <- c;           (26, 10, 16, 31, 25, 16)
10  c <- b;             (26, 10, 10, 31, 25, 16)
11  b <- TMP;           (26, 16, 10, 31, 25, 16)
12  TMP <- a;           (26, 16, 10, 31, 25, 26)
13  a <- e;             (25, 16, 10, 31, 25, 26)
14  e <- TMP;           (25, 16, 10, 31, 26, 26)

Copies happen immediately. A later change to the source register does not change a value already copied.